Renée Zellweger was born Renée Kathleen Zellweger on 25 April 1969, in Katy, Texas to Emil Erich Zellweger, a Swiss-born engineer and Kjellfrid Irene Andreassen, a Norwegian-born former nurse and midwife. In her early years, she attended Katy High School, where she was active in every aspect, as a cheerleader, a gymnast and a member of the debate team. Apart from that, she participated in soccer and powder football, a traditional girls' football game and also took part in the school drama programs.

In 1986, she won the third place in the first-ever Houston Post High School Natural Science Essay Contest for her academic paper about the Karankawas, the indigenous North American Indians, living in southern Texas, along the coast of the Gulf of Mexico. After completing her school studies, Renée enrolled at the University of Texas, Austin in English, along with a drama course as an elective and graduated in 1992, with a degree of Bachelor of Arts in English Literature.

In her junior year, Renée had to take a job as a cocktail waitress in Austin, as her father lost his job and was unable to support her at college. Later she confessed that she learned a lot from there, as much as she did in her classes, learned not to judge people and that things are not black and white. While in college, she also got the opportunity to do a bit part in the Austin-filmed horror-comedy film My Boyfriend’s Back (1993), playing the girl in the beauty shop, which finally got cut. After graduation, Zellweger appeared in several independent and low-budget films, which include uncredited appearances in A Taste for Killing (1992), Dazed and Confused (1993), Murder in the Heartland (1993) and earned her first movie credit with a bit part in Reality Bites (1994), the directorial debut of Ben Stiller, followed by the biographical film 8 Seconds (1994).

In the same year, she got her first main role in the horror film The Return of the Texas Chainsaw Massacre (1994), which went unnoticed and after that, appeared in the crime comedy Love and a 45 (1994), playing the role of Starlene Cheatham, a woman who plans a robbery with her boyfriend, which earned her an Independent Spirit Award for Best Debut Performance and encouraged her to move to Los Angeles.

In the next year, she appeared in the coming-of-age drama Empire Records (1995), followed by The Whole Wide World (1996), which led to her big break in Jerry Maguire (1996), directed by Cameron Bruce Crowe and earned her wider recognition for playing the role of Dorothy Boyd, a single mother and the romantic interest of a glossy sports agent, played by Tom Cruise. The film catapulted her to stardom and she landed her first Screen Actors Guild nomination for Outstanding Performance by a Female Actor in a Supporting Role. Although her next film, the religious drama A Price Above Rubies (1998) flopped at the box office, her performance as Sonia Horowitz, a young woman who finds it difficult to conform to the restrictions imposed on her by the community, was highly applauded by some critics. In the same year, she also starred in One True Thing (1998), along with Meryl Streep and earned appreciation for her performance in the role of Ellen Gulden, a woman who is forced to put her life on hold to care for her mother, who is dying of cancer. After that, she played the female lead Anne in the little-seen romantic comedy The Bachelors (1999).

The career of Renée Zellweger took a turn to another level in 2000, when she starred in the commercially successful comedy Me, Myself & Irene (2000), playing the part of Irene, a woman on the run for what she believes is a false allegation framed by her mob-related ex-boyfriend. In the same year, she also starred in the black comedy, Nurse Betty (2000), along with Morgan Freeman, playing Betty, a Kansas waitress who suffers a nervous breakdown after witnessing her husband's murder.

While she was profusely applauded by both the critics and the commoners for her outstanding performance in the film, she also won her first Golden Globe Award For Best Performance by an Actress. She continued her winning spree with her performance in the title role of Bridget Jones's Diary (2001), earning her second Golden Globe Award nomination for best actress, as well as nominations for her first Academy Award and BAFTA Award for Best Actress in a Leading Role. Her casting in the role created controversy, as she was not British, did not smoke and was too thin to play the chubby, chain-smoking Bridget. But she took the challenge and with strong determination, methodically embarked on gaining the required weight, attended dialect coaching to speak in the English accent, even started smoking herbal cigarettes. Her efforts were duly rewarded, as the film proved to be a massive commercial success.

In 2002, Renée Zellweger appeared in White Oleander (2002), along with Michelle Pfeiffer, to play the role of a former actress, Claire Richards, serving as a foster mother and was nominated for a Satellite Award for Best Actress in a Supporting Role. In the same year, she also earned her second Golden Globe Award and a BAFTA nomination for Best Actress for her performance as the murderess Roxie Hart in the Oscar winning musical drama film Chicago (2002). Following the enormous success of Chicago, she appeared in the romantic comedy Down With Love (2003) and also in the war drama Cold Mountain (2003), opposite Nicole Kidman and Jude Law, playing a woman who helps a farmer following her father's death to win the BAFTA, the Golden Globe, the Screen Actors Guild and the Oscar for best supporting actress. Her other important films in the decade include The Cinderella Man (2005), in which she played the wife of the former world heavyweight boxing champion James Walter Braddock, played by Russell Crowe, the period comedy Leatherheads (2008), the directorial venture of George Clooney, the Western Appaloosa (2008), in which she portrayed a newspaper reporter of Chicago Tribune, opposite Ed Harris and the coming-of-age story My One and Only (2009).

After the release of the road drama My Own Love Song (2010), in which she played a former singer suffering from paralysis, Renée Zellweger took a six-year hiatus from screen acting, as she felt fatigued and even got sick of the sound of her own voice. Following the self exile, she made her career comeback in Bridget Jones’s Baby (2016), the third sequel of the romantic comedy, portraying Jones in her forties and single, discovering that she is pregnant and must find the man behind it. In the crime drama The Whole Truth (2016), she starred opposite Keanu Reeves and portrayed the role of Loretta Lassiter, the mother of a teenager suspected of murdering his wealthy father. She got her first major television role of Anne Montgomery, a mysterious venture capitalist in the Netflix thriller series What/If (2019) and after that, portrayed the Hollywood icon Judy Garland in the biopic Judy (2019), winning an Oscar, BAFTA and Golden Globe Award for best actress.

In her personal life, Renée Zellweger was engaged to actor Jim Carrey from 1999 to 2000 and had a brief relationship with musician Jack White in 2003. Although she married singer Kenny Chesney on 9 May 2005, she obtained an annulment on 20 December 2005. In 2009, she started dating Bradley Cooper, her co-star in Case 39 (2009), which continued till 2011. After that, she was in a relationship with musician Doyle Bramhall II, form 2012 to 2019 and in June 2021, she was reported to be dating English television presenter Ant Anstead.

Throughout her career, Renée Kathleen Zellweger is profusely acclaimed by critics and commoners for her performances in different types of roles and won numerous awards. She has appeared on the covers and photo shoots of several reputed magazines, which include Vanity Fair, Vogue, Allure and Harper’s Bazaar, named part of Hollywood’s Next Wave of Stars and one of the 50 most beautiful people in the world in 2003. Apart from that, she is one of the patrons of the gender equality foundation and a passionate supporter of breast health education and charitable causes.