Janet Jackson was born in Gary, Indiana, the youngest of nine children, to Katherine Esther (née Scruse) and Joseph Walter Jackson. The Jacksons were lower-middle class and devout Jehovah's Witnesses. By the time she was a toddler, her older brothers—Jackie, Tito, Jermaine, Marlon and Michael—were performing music at nightclubs and theaters as The Jackson 5. In March 1969, the group signed a record deal with Motown, and by the end of the year they had recorded the first of four consecutive number one singles. The Jackson 5's success allowed the family to move to the Encino neighborhood of Los Angeles, California in 1971, where they settled in a gated mansion called Hayvenhurst. Although born into a family of professional musicians, Jackson, whose love of horses resulted in a desire to become a race-horse jockey, had no aspiration to become an entertainer. Despite this, her father planned for her to pursue a career in entertainment. Jackson once commented, "No one ever asked me if I wanted to go into show business ... it was expected."

In 1974, at the age of seven, Jackson appeared on stage in Las Vegas, Nevada with her siblings in a routine show at the MGM Casino. Jane Cornwell documented in her biography of the singer, Janet Jackson (2002), that at age eight Joseph Jackson told Janet not to call him "Dad" anymore since he was her manager; he told her she would henceforth address him as "Joseph". She began her career as an actress with the debut of the CBS variety show The Jacksons (1976), in which she appeared with her siblings Tito, Rebbie, Randy, Michael, Marlon, La Toya and Jackie. In 1977, Jackson was selected by producer Norman Lear to play a recurring role as Penny Gordon Woods in the sitcom Good Times. From 1979 to 1980, Jackson starred in A New Kind of Family as Jojo Ashton, and then joined the cast of Diff'rent Strokes, portraying Charlene Duprey from 1981 to 1982. She played a recurring role during the fourth season of the television series Fame as Cleo Hewitt, though she later commented that the series was not a project she enjoyed working on.

Although Jackson was initially apprehensive about starting a music career, she agreed to participate in recording sessions with her family. The first of these, a duet with her brother Randy titled "Love Song for Kids", took place in 1978. When Jackson was sixteen, her father arranged a contract for her with A&M Records. Her debut album, Janet Jackson, produced by soul singers Angela Winbush, René Moore and Leon F. Sylvers III, was released in 1982, the entire production of which was overseen by her father Joseph. It peaked at number six on the Billboard Hot R&B albums chart.

Jackson's second album, Dream Street, was released two years later. Her father recruited her brothers to help produce the album: Marlon co-wrote two of the album's tracks, while Tito, Jackie and Michael provided background vocals. Dream Street reached number nineteen on the R&B albums chart; its sales were less than that of Jackson's debut album. The album's only hit, "Don't Stand Another Chance", peaked at number nine on Billboard's R&B singles chart. In late 1984, Jackson eloped with childhood friend and fellow R&B singer James DeBarge. They divorced shortly afterwards, and the marriage was annulled in mid-1985.

Following the release of Dream Street, Jackson decided to separate her business affairs from her family. She later commented, "I remember trying to tell my father I no longer wanted him to manage me. It would have been easier to have Mother tell him for me, but that was something I had to do for myself." Jackson also stated, "I just wanted to get out of the house, get out from under my father, which was one of the most difficult things that I had to do, telling him that I didn't want to work with him again." A&M Records executive John McClain hired producers Jimmy Jam and Terry Lewis to work with Jackson. Within six weeks, Jackson, Jam and Lewis crafted Jackson's third studio album, Control. Jackson recalled that during the recording of the album, she was threatened by a group of men outside of her hotel in Minneapolis. She stated that "he danger hit home when a couple of guys started stalking me on the street ... Instead of running to Jimmy or Terry for protection, I took a stand. I backed them down. That's how songs like 'Nasty' and 'What Have You Done for Me Lately' were born, out of a sense of self-defense."

Though Jam and Lewis were concerned with achieving cross-over appeal, their primary goal was to create a strong following for the singer within the African-American community first. Jam commented, "e wanted to do an album that would be in every black home in America ... we were going for the black album of all time." Released in February 1986, the album peaked at number one on the Billboard 200. The Newsweek review of Control noted that the album was "an alternative to the sentimental balladry and opulent arrangements of Patti LaBelle and Whitney Houston." Rob Hoerburger of Rolling Stone asserted, "Control is a better album than Diana Ross has made in five years and puts Janet in a position similar to the young Donna Summer's—unwilling to accept novelty status and taking her own steps to rise above it." Five of the album's singles—"What Have You Done for Me Lately", "Nasty", "When I Think of You", "Control", and "Let's Wait Awhile"—peaked within the top 5 of the Billboard Hot 100. "When I Think of You" became Jackson's first single to peak at number one. "The Pleasure Principle" became a top 20 hit, peaking at number fourteen. Most of the Control music videos were choreographed by a then-unknown Paula Abdul. Jonathan Cohen of Billboard magazine commented " accessible sound and spectacularly choreographed videos were irresistible to MTV, and helped the channel evolve from rock programming to a broader, beat-driven musical mix."

Control was certified five times platinum by the Recording Industry Association of America, and has sold over eight million copies worldwide. Billboard credited it as being the fifth best-selling album of 1986 in the United States. It won four American Music Awards, from twelve nominations—a record that has yet to be broken—and was nominated for Album of the Year at the 1987 Grammy Awards. Richard J. Ripani Ph.D., author of The New Blue Music: Changes in Rhythm & Blues, 1950-1999 (2006), observed that the album was one of the first successful records to influence the rise of new jack swing, incorporating R&B, funk, jazz, soul and various production techniques which emerged in the mid-1980s. The success of Control, according to Ripani, bridged the gap between R&B and rap music.

In September 1989, Jackson released her fourth album, Janet Jackson's Rhythm Nation 1814. Though executives at A&M wanted an album similar to Control, Jackson was unwilling to compromise her artistic integrity, and was determined to imbue her music with a socially conscious message that complimented her songs about love and relationships. Jackson stated, "I'm not naive—I know an album or a song can't change the world. I just want my music and my dance to catch the audience's attention, and to hold it long enough for them to listen to the lyrics and what we're saying." Producer Jimmy Jam told The Boston Globe, "We would always have a TV turned on, usually to CNN ... And I think the social slant of songs like Rhythm Nation, State of the World and The Knowledge came from that." Rolling Stone magazine's Vince Aletti observed Jackson shifted from "personal freedom to more universal concerns—injustice, illiteracy, crime, drugs—without missing a beat." Richard J. Ripani observed that the album, much like its predecessor, contained heavy styling of new jack swing; the use of sample loop, triple swing, rap vocals and blues notes are present in the album's title-track "Rhythm Nation".

After debuting at number one on the Billboard 200, the album was later certified six times platinum and eventually sold over eight million copies worldwide. The release became the only album in history to produce number one hits on the Billboard Hot 100 in three separate calendar years—"Miss You Much" in 1989, "Escapade" and "Black Cat" in 1990, and "Love Will Never Do (Without You)" in 1991—and the only album in the history of the Hot 100 to have seven top 5 hit singles. The corresponding music video for "Rhythm Nation" won the 1989 Grammy Award for Best Long Form Music Video. Billboard named Rhythm Nation 1814 the number-one selling album of the year in 1990, winning multiple music awards. Jackson was dubbed a reigning "Princess of Pop" by the Chicago Tribune. Although some attributed Jackson's accomplishments to her producers, Jimmy Jam stated "when someone says, 'Well, she brought in Jimmy Jam and Terry Lewis,' you've got to remember that we weren't exactly ... Quincy Jones ... 'Control' was our first smash. The same with Paula. It wasn't like Janet Fred Astaire ... She took a chance on all of us."

The Rhythm Nation 1814 Tour, Jackson's first world tour in support of a studio album, aimed to recreate the "award–winning, visually innovative" music videos of Rhythm Nation 1814 and Control, and was described as "an elaborately choreographed spectacle" by Entertainment Weekly. As Jackson began her tour, she was acknowledged for the cultural impact of her music. Joel Selvin of the San Francisco Chronicle wrote "the 23-year-old has been making smash hit records for four years, becoming a fixture on MTV and a major role model to teenage girls across the country", and William Allen, then-executive vice president of the United Negro College Fund, told the Los Angeles Times, "Jackson is a role model for all young people to emulate and the message she has gotten to the young people of this country through the lyrics of 'Rhythm Nation 1814' is having positive effects." With an attendance of more than two million patrons, the Rhythm Nation 1814 Tour remains the most successful debut tour by any recording artist. Routledge International Encyclopedia of Women: Global Women's Issues and Knowledge (2000) documented that Jackson's success during this time period placed her on par with several other recording artists, including her older brother Michael Jackson, Madonna and Tina Turner.

With the release of Rhythm Nation 1814, Jackson fulfilled her contract with A&M Records. In 1991, after being approached personally by Virgin Records owner Richard Branson, she signed a highly publicized multi-million dollar contract with the label. The contract value was estimated between $32–50 million, and she became the highest paid female recording artist in contemporary music. That same year, Jackson secretly entered into her second marriage with long-term friend—dancer, songwriter and director René Elizondo, Jr. In May 1992, Jackson recorded a song entitled "The Best Things in Life Are Free" with Luther Vandross, featuring Bell Biv Devoe and Ralph Tresvant, for the Mo' Money film soundtrack.

In May 1993, Jackson's fifth studio album entitled janet. (pronounced "Janet, period."), was released by Virgin Records and debuted at number one on the Billboard 200. Jackson commented, "... ertain people feel I'm just riding on my last name ... That's why I just put my first name on janet. and why I never asked my brothers to write or produce music for me." The New Rolling Stone Album Guide (2004) commented that the album's number one hit single "That's the Way Love Goes"—winner of the 1994 Grammy Award for Best R&B Song—and the top 10 singles "If", "Because of Love", "You Want This", and "Any Time, Any Place", all contained "grown-up desires". Rolling Stone wrote: "As princess of America's black royal family, everything Janet Jackson does is important. Whether proclaiming herself in charge of her life, as she did on Control (1986), or commander in chief of a rhythm army dancing to fight society's problems (Rhythm Nation 1814, from 1989), she's influential. And when she announces her sexual maturity, as she does on her new album, Janet., it's a cultural moment." Robert Johnson of San Antonio Express-News wrote that the album ranges from "dreamy and sensual" to "downright erotic", and although " isn't perfect ... it should be enough to make her the Queen of Pop." Conversely, David Browne of Entertainment Weekly gave it a moderate rating, asserting "her wispy voice is often smothered by her two male producers", and regarded janet. as a "blatant rip-off of the club-beat style of Madonna's Erotica." janet. was later certified six times platinum by the RIAA, with worldwide sales exceeding ten million copies.

In July 1993, Jackson made her film debut in Poetic Justice. Rolling Stone described Jackson's performance as "a beguiling film debut" despite her inexperience, while the Washington Post considered her "believably eccentric". Jackson's ballad "Again" was featured on the film's soundtrack, and garnered a nomination for the Academy Award for Best Original Song.

In September 1993, Jackson appeared topless on the cover of Rolling Stone magazine with the hands of her then-husband René Elizondo, Jr. covering her breasts. The photograph is the original full-length version of the cropped image used on the cover of the janet. album, shot by Patrick Demarchelier. Sonia Murray of The Vancouver Sun later reported, "Jackson, 27, remains clearly established as both role model and sex symbol; the Rolling Stone photo of Jackson ... became one of the most recognizable, and most lampooned, magazine covers of the year." In the cover story, "Sexual Healing" by David Ritz, Jackson explained, "... sex has been an important part of me for several years. But it just hasn't blossomed publicly until now. I've had to go through some changes and shed some old attitudes before feeling completely comfortable with my body. Listening to my new record, people intuitively understand the change in me." Ritz likened Jackson's transformation to Marvin Gaye as he stated, "ust as Gaye moved from What's Going On to Let's Get It On, from the austere to the ecstatic, Janet, every bit as serious-minded as Marvin, moved from Rhythm Nation to janet., her statement of sexual liberation." Jackson's second world tour—the janet. Tour—garnered critical acclaim as Michael Snyder of the San Francisco Chronicle described Jackson's stage performance as erasing the line between "stadium-size pop music concerts and full-scale theatrical extravaganzas", and Steve Pick of the St. Louis Post-Dispatch observed Jackson's show made the janet. album's numerous hit singles more effective with her "larger-than-life stage persona".

During this time period, Jackson's brother Michael Jackson was immersed in a child sex abuse scandal, of which he denied any wrongdoing. Jackson gave moral support to her brother, and denied allegations made by her sister La Toya Jackson in her book La Toya: Growing up in the Jackson Family (1991) that their parents had abused her and her siblings as children. In an interview with Lynn Norment of Ebony, Jackson commented on her sister's then-estrangement from the family, stating, "her has ... brainwashed her so much she keeps herself away from us." Norment reported during the recording of janet., "LaToya suddenly showed up and created a scene at the Minneapolis recording studio", despite the fact that " sister had ignored her calls for four years prior to that." In addition, Jackson criticized her brother Jermaine Jackson for attacking Michael in his 1991 single "Word To The Badd". She later collaborated with her brother Michael on "Scream", the lead single from his 1995 album HIStory, which was written by both siblings as a response to the media scrutiny he suffered from being accused of child sexual abuse. The song debuted at number five on the Hot 100 singles chart, becoming the first song ever to debut in the top 5. Scream is featured in the Guinness Book of Records as the "Most Expensive Music Video Ever Made" at a cost of $7 million. Jackson and her brother won the 1995 Grammy Award for Best Short Form Music Video for Scream.

In October 1995, Jackson's first compilation album, Design of a Decade 1986/1996, was released via A&M Records and debuted at number three on the Billboard 200. The lead single "Runaway" peaked at number three on the Hot 100. Design of a Decade 1986/1996 was certified two times platinum by the RIAA. In January 1996, Jackson renewed her contract with Virgin Records for a reported $80 million dollars. The contract established her as the then-highest paid recording artist in contemporary music, surpassing the recording industry's then-unparalleled $60 million dollar contracts earned by her brother, Michael Jackson and Madonna.

During the two year period prior to the release of her sixth studio album, The Velvet Rope, Jackson reportedly suffered from depression and anxiety. Michael Saunders of The Boston Globe considered the album to be an introspective look into Jackson's bout with depression, describing it as a "critical self-examination and an audio journal of a woman's road to self-discovery." According to Jackson, "e've all driven by premieres or nightclubs and have seen the rope separating those who can enter and those who can't. Well, there's also a velvet rope we have inside us, keeping others from knowing our feelings. In The Velvet Rope, I'm trying to expose and explore those feelings ... During my life, I've been on both sides of the rope. At times, especially during my childhood, I felt left out and alone. At times I felt misunderstood." The Velvet Rope also introduced sadomasochism into Jackson's music. Eric Henderson of Slant wrote, "The Velvet Rope is a richly dark masterwork that illustrates that, amid the whips and chains, there is nothing sexier than emotional nakedness."

Released in October 1997, The Velvet Rope debuted at number one on the Billboard 200 and the RIAA later certified the album three times platinum. In August 1997 the album's lead single, "Got 'Til It's Gone", was released to radio, peaking at number 36 on the Billboard Hot 100 Airplay. The single sampled the Joni Mitchell song "Big Yellow Taxi", and featured a cameo appearance by rapper Q-Tip. Got 'Til It's Gone won the 1997 Grammy Award for Best Short Form Music Video. The album's second single "Together Again", became Jackson's eighth number one hit on the Billboard Hot 100 singles chart, and placing her on par with Elton John, Diana Ross, and The Rolling Stones. The single spent a record 46 weeks on the Hot 100, as well as spending 19 weeks on the UK singles chart. "I Get Lonely" peaked at number three on the Hot 100.

Jackson donated a portion of the proceeds earned from "Together Again" to the American Foundation for AIDS Research. Neil McCormick of The Daily Telegraph observed, " even makes a bid for gay icon status, delivering a diva-ish performance reminiscent of Diana Ross on 'Together Again' (a post-Aids pop song), singing a paean to homosexuality on the jazzy 'Free Xone' and climaxing (if that's the right word) with a bizarre lesbian reinterpretation of Rod Stewart's 'Tonight's the Night'." Rolling Stone regarded "Free Xone" as the album's "best song", describing it as an "anti-homophobia track shifts moods and tempos on a dime, segueing from a Prince-like jam to a masterful sample from Archie Bell and the Drells' 'Tighten Up'." The Velvet Rope was honored by the National Black Lesbian and Gay Leadership Forum, and received the award for Outstanding Music Album at the 9th Annual GLAAD Media Awards.

In 1998, Jackson began the The Velvet Rope Tour, an international trek that included Europe, North America, Africa, Asia, New Zealand and Australia. Robert Hilburn of the The Los Angeles Times reported, "here is so much of the ambition and glamour of a Broadway musical in Janet Jackson's new Velvet Rope tour that it's only fitting that the concert program credits her as the show's 'creator and director'." Jackson's HBO special, The Velvet Rope: Live in Madison Square Garden, was watched by more than fifteen million viewers. The two hour concert beat the ratings of all four major networks in homes that were subscribed to HBO. The following month, Jackson separated from Elizondo Jr. As her world tour came to a close in 1999, Jackson lent guest vocals to a number of songs by other artists, including Shaggy's "Luv Me, Luv Me", for the soundtrack to How Stella Got Her Groove Back, "God's Stepchild" from the Down on the Delta soundtrack, "Girlfriend/Boyfriend" with BLACKstreet, and "What's It Gonna Be?!" with Busta Rhymes. Jackson also performed a duet with Elton John for the song "I Know the Truth". At the 1999 World Music Awards, Jackson received the Legend Award alongside Cher for "lifelong contribution to the music industry and outstanding contribution to the pop industry." As 1999 ended, Billboard magazine ranked Jackson as the second most successful artist of the decade, behind Mariah Carey.

In July 2000, Jackson appeared in her second film, Nutty Professor II: The Klumps, as Professor Denise Gaines, opposite Eddie Murphy. The film became Jackson's second to open at number one at the box office, grossing an estimated $42.7 million dollars in its opening weekend. Her contribution to the film's soundtrack, "Doesn't Really Matter", became her ninth number one Billboard Hot 100 single. In the same year, Jackson's husband filed for divorce. Jeff Gordinier of Entertainment Weekly reported that for eight of the thirteen years Jackson and Elizondo had known one another, " were married—a fact they managed to hide not only from the international press but from Jackson's own father." Elizondo filed a multi-million dollar lawsuit against Jackson, estimated between $10–25 million; they did not reach a settlement until 2003.

Jackson was awarded a top honor from the American Music Awards—the Award of Merit—in March 2001 for "her finely crafted, critically acclaimed and socially conscious, multi-platinum albums." Jackson became the inaugural honoree of the "mtvICON" award, "an annual recognition of artists who have made significant contributions to music, music video and pop culture while tremendously impacting the MTV generation." Jackson's seventh album, All for You, was released in April 2001, debuting at number one on the Billboard 200. Selling 605,000 copies, All For You had the highest first-week sales total of Jackson's career. Stephen Thomas Erlewine of Allmusic stated " created a record that's luxurious and sensual, spreading leisurely over its 70 minutes, luring you in even when you know better", and Jon Pareles of The New York Times commented, "s other rhythm and blues strips down to match the angularity of hip-hop, Ms. Jackson luxuriates in textures as dizzying as a new infatuation."

The album's title-track, "All for You", debuted on the Hot 100 at number fourteen, the highest debut ever for a single that was not commercially available. Teri VanHorn of MTV dubbed Jackson "Queen of Radio" as the single made radio airplay history, " added to every pop, rhythmic and urban radio station that reports to the national trade magazine Radio & Records" in its first week. The single peaked at number one, where it topped the Hot 100 for seven weeks. Jackson received the 2001 Grammy Award for Best Dance Recording for "All for You". The second single, "Someone to Call My Lover", which contained a heavy guitar loop of America's "Ventura Highway", peaked at number three on the Hot 100. All For You sold more than three million copies in America, and was certified double platinum by the RIAA.

Reviews for Jackson's All for You Tour drew comparison to that of her contemporary rivals. The Los Angeles Times' David Massey reported that compared to Madonna's Drowned World Tour, "Janet outdid the Material Girl by a mile ... And the gall to bring Britney Spears' name into the picture by saying Janet's show is like Britney's? Hello, it's the other way around!." Similarly, reporter Rudy Scalese complimented Jackson's performance, stating, "Janet Jackson hasn't skipped a beat. She is still the Queen of Pop." In contrast, Charles Passy of The Palm Beach Post commented, "eeing Jackson's show after Madonna's 'Drowned World' tour is to realize the limits of the pop-concert format. Madonna pushed those limits and came up with a daring hybrid of circus, theater and music. Jackson, on the other hand, lived within the constraints." Jackson donated a portion of the proceeds from the tour's ticket sales to the Boys & Girls Clubs of America, with President Roxanne Spillett stating, "he increased awareness she will bring to our cause, along with her generous financial contribution, will help us reach an even greater number of young people in search of hope and opportunity."

In 2002, Jackson collaborated with reggae singer Beenie Man on the song "Feel It Boy". Jackson later admitted regret over the collaboration after discovering Beenie Man's music often contained homophobic lyrics, and she issued an apology to her gay following in an article contained in The Voice. Jackson also began her relationship with record producer Jermaine Dupri that same year.

For the Super Bowl XXXVIII halftime show in February 2004, Jackson performed a medley of her singles "All for You" and "Rhythm Nation"; she then performed alongside Justin Timberlake. As Timberlake sang the lyric "gonna have you naked by the end of this song" from his single "Rock Your Body", he tore open Jackson's top, exposing her right breast. After the performance, Jackson apologized, calling it an accident, and said that Timberlake was supposed to pull away the bustier and leave the red-lace bra intact. She further commented, "I am really sorry if I offended anyone. That was truly not my intention ... MTV, CBS, the NFL had no knowledge of this whatsoever, and unfortunately, the whole thing went wrong in the end." Timberlake also issued an apology, calling the accident a "wardrobe malfunction". Time magazine reported that the incident became the most replayed moment in TiVo history and Monte Burke of Forbes magazine reported "he fleeting moment enticed an estimated 35,000 new subscribers to sign up." Jackson was later listed in the 2007 edition of Guinness World Records as "Most Searched in Internet History" and the "Most Searched for News Item". CBS, the NFL, and MTV (CBS's sister network, which produced the halftime show), denied any knowledge of, and all responsibility for, the incident. Still, the Federal Communications Commission continued an investigation, ultimately losing its appeal for a $550,000 fine against CBS.

As a result of the incident, CBS would only allow Jackson and Timberlake to appear during the 46th Grammy Awards ceremony if they each made a public apology to the network, without attributing the incident to a "wardrobe malfunction". Timberlake issued an apology, but Jackson refused. Jermaine Dupri resigned from his position on the Grammy Awards committee as a result. The controversy halted plans for Jackson to star in a made-for-TV biopic on the life on singer Lena Horne for ABC-TV. Though Horne was reportedly displeased by the Super Bowl incident and insisted that ABC pull Jackson from the project, according to Jackson's representatives, she withdrew from the project willingly.

In March 2004, Jackson's eighth studio album, Damita Jo, was released debuting at number two on the Billboard 200. Steve Jones of USA Today reported, "he album, which takes its title from middle name, shows several sides of her personality." During the interview Jackson commented, "he album is about love ... Damita Jo is one of the characters that lives inside of me." Lorraine Ali of Newsweek reported Jackson's album depicts vulnerability. She commented, "and who would know better what it's like to stand exposed? Her Super Bowl debacle/accident/publicity stunt aside, she's the ninth and youngest child of pop culture's most scrutinized celebrity family."

Jackson appeared as a host of Saturday Night Live on April 10, 2004, where she performed a skit that parodied the Super Bowl incident. She also appeared in the television sitcom Will & Grace playing herself, interacting with sitcom characters Karen Walker and Jack McFarland as Jack was auditioning to be one of her back-up dancers. By the end of 2004, Damita Jo had sold 942,000 copies in the United States and was later certified platinum by the RIAA. Although the album debuted at number two, its three singles all failed to become top 40 hits. Keith Caulfield of Billboard commented, "or a singles artist like Jackson, who has racked up 27 top 10 Hot 100 singles in her career, including 10 No. 1s, this could probably be considered a disappointment." Billboard's Clover Hope reported Damita Jo "was largely overshadowed by the Super Bowl fiasco" and that Jermaine Dupri, the then-president of the urban music department at Virgin Records, expressed "sentiments of nonsupport" from the company.

In November 2004, Jackson was honored as an African-American role model by 100 Black Men of America, Inc., who presented her with the "organization's Artistic Achievement Award saluting 'a career that has gone from success to greater success'." Though the New York Amsterdam News reported "here were a number of attendees who expressed dismay over presenting an award to the 38-year-old performer" due to the Super Bowl incident, the organization's President Paul Williams responded, "n individual's worth can't be judged by a single moment in that person's life." In June 2005, Jackson was honored with a Humanitarian Award by the Human Rights Campaign and AIDS Project Los Angeles, in recognition of her work and involvement in raising money for AIDS charities.

To promote her ninth studio album, 20 Y.O., Jackson appeared on the cover of Us Weekly in June 2006, which became the magazine's best-selling issue. Virgin Records released 20 Y.O. in September 2006, which debuted at number two on the Billboard 200. Janine Coveney of Billboard reported the album title, 20 Years Old, represents "a celebration of the joyful liberation and history-making musical style of her 1986 breakthrough album, Control." Jackson stated "his album takes me to a place where I haven't been in a while: R&B and dance ... The album also features samples from music that inspired me 20, 25 years ago."

Rolling Stone magazine's Evan Serpick remarked "he title of Janet Jackson's latest album refers to the two decades since she released her breakthrough, Control, with hits like 'Nasty' and 'What Have You Done for Me Lately.' If we were her, we wouldn't make the comparison." However, Glenn Gamboa of Newsday gave the album a positive rating, stating that "n '20 Y.O.' she skips all that drama of breaking free and asserting herself. She also keeps most of the tie-me-up, tie-me-down sexual raunch of her recent albums in the closet. This album is all about dancing and returning to her R&B roots." The album's lead single "Call on Me," a duet with rapper Nelly, peaked at number twenty-five on the Hot 100. 20 Y.O. was certified platinum by the RIAA. Billboard magazine reported the release of 20 Y.O. satisfied Jackson's contract with Virgin Records; Jermaine Dupri, who co-produced 20 Y.O., left his position as head of urban music at Virgin following the "disappointing performance" of Jackson's album.

In January 2007, Jackson was ranked the seventh richest woman in the entertainment business by Forbes magazine, having amassed a fortune of over $150 million. Later that year, Jackson starred opposite Tyler Perry as a psychotherapist named Patrica in the feature film Why Did I Get Married? The film opened at number one at the box office, grossing $21.4 million in its first week. Wesley Morris of The Boston Globe commented that Jackson portrayed her character with "soft authority". In February 2008, Jackson won the NAACP Image Award for Outstanding Supporting Actress in a Motion Picture for her role.

In July 2007, Jackson changed labels and signed a record contract with Island Records. Jackson's tenth studio album, Discipline, was released in February 2008, by the Island Def Jam Music Group, debuting on the Billboard 200 at number one. Jackson and Jermaine Dupri severed as executive producers, long-term collaborators Jimmy Jam and Terry Lewis did not contribute, and Discipline was the first album on which Jackson did not co-write any of the material since 1984's Dream Street. Paul Grein of Yahoo! Music observed that with six number one studio albums, Jackson had "surpasse her brother Michael Jackson, who has amassed five albums." In an interview with Larry King of CNN, Jackson commented, "Discipline. It's the title track on the album ... But I wanted to name the album Discipline because it has a lot of different meanings for me but the most important would be work—to have done this for as long as I have ... And to have had the success that I've had—not excluding God by any means—but it takes a great deal of focus."

Margeaux Watson of Entertainment Weekly referred to the lyrical content as "cheesy", while Dan Cairns of The Sunday Times called the album "bizarre". However, Allmusic's Andy Kellman described the album as "innocent, universal inviting as anything else in Janet's past." Prior to the album's debut, the first single from the album, "Feedback", was leaked to select radio stations in the United States in December 2007. The single peaked at number nineteen on the Hot 100. In April 2008, Jackson received the Vanguard Award, a media award from the Gay & Lesbian Alliance Against Defamation at the 19th Annual GLAAD Media Awards. The award honors members of the entertainment community who have made a significant difference in promoting equal rights for LGBT people. GLAAD President Neil G. Giuliano commented, "Ms. Jackson has a tremendous following inside the LGBT community and out, and having her stand with us against the defamation that LGBT people still face in our country is extremely significant."

Jackson's fifth concert tour—the Rock Witchu Tour—began in September 2008. Amy O'Brian of The Vancouver Sun described Jackson's stage show at the GM Place as a "high-voltage performance". According to O'Brian, "ith an ear-piercing blast of pyrotechnics, a fog of thick cloud and dancers that popped up out of the stage and runway, Jackson proved within the first minutes that she didn't choose the low-budget route for her Rock Witchu Tour." Similarly, Jim Harrington of The Oakland Tribune offered a positive review, stating: "Like Jackson's previous tours, 'Rock Witchu' was a flashy, high-budget extravaganza built on well-choreographed dance routines and plenty of theatrics." That same month, Jackson and her record label parted ways through mutual agreement. In the fourteen months Jackson had been associated with Island Def Jam, her debut album under the label had sold 415,000 copies in the United States and spent fourteen weeks on the Billboard charts. Billboard reported that due to Jackson's dissatisfaction with her album's promotion, "the label agreed to dissolve their relationship with the artist at her request."