Jennifer Lopez was born and grew up in the South Bronx, New York to Puerto Rican parents Guadalupe Rodríguez, a kindergarten teacher, and David Lopez, a computer specialist. She has two siblings, Lynda and Leslie. Lopez spent her entire academic career in Catholic schools, finishing at the all-girls Preston High School, in the Bronx. She financed singing and dancing lessons for herself from the age of 19. After attending Baruch College for one semester, Lopez divided her time between working in a legal office, dance classes, and dance performances in Manhattan night clubs. After months of auditioning for dance roles, Lopez was selected as a dancer for various rap music videos, a 1990 episode of Yo! MTV Raps, and as a backup dancer for the New Kids on the Block and their performance of their song "Games" for the American Music Awards in 1991. After being rejected twice, Lopez gained her first regular high-profile job as a "Fly Girl" dancer on the television comedy program In Living Color in 1990. Soon after, Lopez became a backup dancer for Janet Jackson and made an appearance in her 1993 video "That's the Way Love Goes".

Lopez appeared on the short-lived television programs South Central, Second Chances, and Hotel Malibu, and the made-for-television film Nurses on the Line: The Crash of Flight 7. Lopez broke into the big screen in the 1995 drama My Family and then appeared opposite Wesley Snipes in the action film Money Train. Lopez has played roles in Francis Ford Coppola's 1996 comedy Jack starring Robin Williams, and the 1997 thriller Blood and Wine with Jack Nicholson. Lopez played the lead role in the 1997 film Selena for which she was nominated for the Golden Globe Award for "Best Actress - Motion Picture Musical or Comedy" in 1998. She became the first Hispanic actress to get paid $1 million or more for a film role. Some of her other critically-acclaimed films include Out of Sight, The Cell, An Unfinished Life, and Shall We Dance?. Two independent films produced by Lopez were well-received at film festivals: El Cantante at the Toronto International Film Festival, and Bordertown at the Brussels film festival. Other modestly successful films include The Wedding Planner, Maid in Manhattan, Monster-in-Law, and Enough. Gigli, however, would be a critical and commercial disappointment. In August 2007, Lopez collaborated on the feature film, El Cantante, with her husband singer-actor Marc Anthony. The film is in English, with a creative use of subtitles for songs with Spanish lyrics.

In May 2006, Lopez was the executive producer of the eight-episode reality show, DanceLife, which ran on MTV beginning January 15, 2007. Lopez helped select the show's participants and made cameo appearances. She then served as executive producer of a miniseries broadcast on Univisión. Titled after her CD Como Ama Una Mujer, it ran in five episodes from October 30 to November 27, 2007, and starred Christian Borrero and Adriana Cruz.

Lopez signed a contract as star and executive producer of an unscripted reality series for TLC, a division of Discovery Communications Inc. The series will show the launching of her new fragrance, and will not focus on her family.

Lopez is one of the highest-paid actresses in Hollywood and the highest-paid Latin actress in Hollywood history, though she's never had a film grossing over $100 million in the U.S. Lopez appeared in the 2007 Guinness World Records as the most powerful actress. She was on the The Hollywood Reporter's list of the top ten actress salaries in 2002, 2003, and 2004. She received $15,000,000 for her role in Monster-in-Law. Her top-grossing film domestically is Maid in Manhattan which grossed $94,011,225, and her most successful international film, Shall We Dance?, grossed $112,238,000 at the international box office. Domestically, Shall We Dance? grossed $57,890,460 and a total of $170,128,460 worldwide.

Lopez has sold over 48 million albums worldwide. Lopez made the 2007 Forbes magazine's list of The 20 Richest Women In Entertainment, ranking ninth. Her wealth is estimated to be $110 million.

Lopez's debut album On the 6, a reference to the 6 subway line she used to take growing up in Castle Hill was released on June 1, 1999, and reached the top ten of the Billboard 200. The album featured the Billboard Hot 100 number-one lead single, "If You Had My Love",, as well as the top ten hit "Waiting for Tonight". The album also featured a Spanish language, Latin-flavored duet "No Me Ames" with Marc Anthony (who later would become her husband.) Though "No Me Ames" never had a commercial release, it reached number one on the U.S. Hot Latin Tracks. On the 6 featured guest artists such as Big Pun and Fat Joe on the track "Feelin' So Good", which had moderate success on the Billboard Hot 100. "Let's Get Loud", the final single, earned Lopez a Grammy Award nomination in the "Best Dance Recording" category in 2001 Grammy Awards. "Waiting for Tonight" was nominated for the same category the previous year. "No Me Ames" received two nominations at the 2000 Latin Grammy Awards — "Best Pop Duo/Group with Vocal Performance" and "Best Music Video".

Lopez's second album, J. Lo, was released on January 23, 2001 and debuted at number one on the Billboard 200. When her film The Wedding Planner achieved number one shortly after, Lopez become the first actress-singer to have a film and an album at number one in the same week. The lead single, "Love Don't Cost a Thing", was her first number-one single in the United Kingdom and took her into the top five on the U.S. Billboard Hot 100. She followed it up with "Play" which gave her another top twenty hit on the Billboard Hot 100 and reached number three in the UK. Her next two singles were "I'm Real" and "Ain't It Funny" which were quickly rising up the charts. To capitalize on this, Lopez asked The Inc. Records (then known as Murder Inc.) to remix both songs, which featured rap artists Ja Rule (on both) and Caddillac Tah (on the "Ain't It Funny" remix). Both remixes reached number one on the Billboard Hot 100 for several weeks. She re-released J. Lo on her thirty-second birthday with the remix of "I'm Real" as a bonus track. Also, "Si Ya Se Acabó" was released in Spain, due to the success "Que Ironia".

Following the success of the re-release of J. Lo, Lopez decided to devote an entire album to the remixing effort, releasing J to tha L-O!: The Remixes, on February 5, 2002. This album debuted at number one on the Billboard 200, becoming the first remix album in history to debut at the top on the chart. Featured artists on J to tha L-O!: The Remixes included P. Diddy, Fat Joe, and Nas, and the album included rare dance and hip hop remixes of past singles. It is the third all-time biggest-selling remix album in the world, after Michael Jackson's Blood on the Dance Floor: HIStory in the Mix (1997) and Madonna's You Can Dance (1987).

On November 26, 2002, Lopez released her third studio album, This Is Me... Then, which reached number two on the Billboard 200 and spawned four singles: "Jenny from the Block" (featuring Jadakiss and Styles P), which reached number three on the Billboard Hot 100; "All I Have" (featuring LL Cool J), which spent multiple weeks at number one; "I'm Glad"; and "Baby I Love U!". The album included a cover of Carly Simon's 1978 "You Belong to Me".

After a year away from the music scene, Lopez released her fourth studio album, Rebirth, on March 1, 2005. Although debuting and peaking at number two on the Billboard 200, the album quickly fell off the charts. It spawned the hit "Get Right", which reached the top fifteen in the U.S. and became her second Platinum hit (after "If You Had My Love"). "Get Right" was also successful in the UK, becoming her second number-one single there. The second single, "Hold You Down", which featured Fat Joe, reached number sixty-four on the U.S. Hot 100; it peaked at number six in the UK and ascended to the top twenty in Australia. Another song, "Cherry Pie", was slated for a release in late 2005, but the plans to make a video were canceled as the album sales were definitely too weak and the promotion budget exceeded. It was released to radio stations in Spain. Rebirth was certified Platinum in the U.S. by the RIAA. Lopez was then featured on LL Cool J's single "Control Myself", which was released on February 1, 2006. It reached number four on the U.S. Billboard Hot 100 and number two on the UK Singles Chart. It was Lopez's first U.S. top ten hit in three years.

Lopez officially released her first full Spanish-language album, called Como Ama una Mujer, on March 27, 2007 in the U.S. and March 23, 2007 in Europe. Her husband, singer Marc Anthony, produced the album with Estefano, except for "Qué Hiciste", which Anthony co-produced with Julio Reyes. The album peaked at number ten on the U.S. Billboard 200, number one on the U.S. Top Latin Albums (for four straight weeks), number one on the U.S. Latin Pop Albums (for seven straight weeks), and number one hundred and thirty-one in the UK. The album did well in Europe peaking at number three on the albums chart, mainly due to the big success in countries like Switzerland, Italy, Spain, France, Belgium, Greece, Germany, Austria, and Portugal. The lead single, "Qué Hiciste" (Spanish for "What Did You Do"), was officially released to radio stations in January 2007. Since then, it has peaked at eighty-six on the U.S. Billboard Hot 100 and number one on the Hot Latin Songs and the Hot Dance Club Play. It also went top ten on the European chart. The video for the song was the first Spanish-language video to peak at number one on MTV's Total Request Live daily countdown. The second single released is called "Me Haces Falta" and the third is "Por Arriesgarnos". Lopez won an American Music Award as the Favorite Latin Artist in 2007. Como Ama una Mujer holds the record for the best opening week internet sales for a Spanish album. With Como Ama Una Mujer, Jennifer Lopez is one of the few performers to debut in the top 10 of the Billboard 200 with a Spanish album.

Just over six months later, on October 9, 2007, Lopez released her fifth English studio album (sixth studio album overall). She collaborated with producers Midi Mafia, J. R. Rotem, Lynn and Wade and Ryan Tedder, with Rotem working on some tracks with writing partner Evan "Kidd" Bogart. Earlier, on August 26, 2007, ABC premiered a promo for the fourth season of Desperate Housewives, featuring a snippet of the song "Mile In These Shoes". "Do It Well" was released as the lead single and reached the top 20 in many countries. "Hold It, Don't Drop It" was released as the second single in only in some countries from Europe.

Lopez will celebrate a decade of her singing career with the upcoming greatest hits album "Still From The Block". The album will feature her biggest hits from 1999 to 2009 like the Billboard Hot 100 number-one singles, "If You Had My Love", "I'm Real", "Ain't It Funny", "All I Have", as well as the top ten hits "Waiting For Tonight", "Jenny From The Block", "Love Don't Cost A Thing", "Get Right", "I'm Gonna Be Alright", and her Billboard Latin Tracks number-one Spanish singles "No Me Ames" and "Que Hiciste". It will also feature some new tracks, including the 1st single "Still From The Block" produced by Swizz Beatz. The tentative release date is February 10th 2009.