Witherspoon was born in New Orleans, Louisiana to John Witherspoon, a surgeon, and Betty Reese, a nurse and college professor. She is a direct descendant of Scottish-born John Witherspoon, a signer of the United States Declaration of Independence and sixth president of Princeton University, who was also a Presbyterian minister. Because her father worked for the US military in Wiesbaden, Germany, she lived there for four years as a small child. After returning to the United States, Witherspoon spent much of her childhood and adolescence in Nashville, Tennessee. She has an older brother, John, who works as a real estate broker. After graduating from the prestigious private all-girl's Harpeth Hall School in Nashville, she attended Stanford University as a literature major. After completing a year of her studies, she left Stanford to pursue her acting career.

Witherspoon began her career in local commercials. Her first role was in a 1991 made-for-TV movie called Wildflower, directed by Diane Keaton and starring Beau Bridges, William McNamara, and Patricia Arquette. That same year, at age 14, Witherspoon attended an open casting call for The Man in the Moon, intending to audition as a bit player. She was instead cast in the lead role, immediately capturing the attention of critics. Since, she has built up an impressive filmography, playing both comedic and dramatic roles, including performances as Vanessa in Freeway and Tracy Flick in Election. She was the voice of the animated character Greta Wolfecastle in an episode of The Simpsons. She achieved fame for her role in 2001's Legally Blonde, and its sequel Legally Blonde 2 for which she received a reported $15 million paycheck, making her one of Hollywood's top-paid actresses. She has garnered critical praise and awards for her turn as June Carter Cash in Walk the Line. Before her death in 2003, Carter Cash personally selected Witherspoon to play her. Witherspoon won the Golden Globe Award for Best Actress - Motion Picture Musical or Comedy, NYFCC, the FFCC, the SFFCC Award for Best Actress, the British Academy's BAFTA for best actress in a lead role, the "Favorite Leading Lady" at the 32nd Annual People's Choice Awards, and the Academy Award for Best Actress for this role.

Witherspoon runs a production company, Type A Productions, with partner Laura Siegel. The company is named after Witherspoon childhood nickname "Little Miss Type A."

On February 28, 2006, it was reported that Witherspoon will beat Julia Roberts' record for the highest paid actress of all time when she is paid $29 million for an upcoming horror film Our Family Trouble, which will beat Roberts' $25 million 2004 salary for Mona Lisa Smile. However, on March 2, 2006, Witherspoon's publicist denied the salary increase to syndicated entertainment show Access Hollywood.


Witherspoon met actor Ryan Phillippe at her 21st birthday party in March 1997. The pair were engaged in December 1998. Soon after, the couple starred together in the box office hit, Cruel Intentions. They were married on a plantation in Charleston, South Carolina on June 5, 1999. They have two children together: daughter Ava Elizabeth, born September 9, 1999, and son Deacon, born October 23, 2003. Ava is named after Phillippe's grandmother, and Deacon after one of his distant relatives.


Witherspoon promoting Vanity Fair.Witherspoon and Phillippe have a pact that one of them will always be a full-time parent to the children, and they thus alternate filming schedules. Witherspoon is known for being a very hands-on mother, and she and her husband claim to have never employed a full-time nanny. The family resides in a gated community in the Los Angeles neighborhood of Brentwood.


In September 2005, Witherspoon and her children were celebrating daughter Ava's sixth birthday at Disney's California Adventure theme park when they were approached by paparazzi photographer, Todd Wallace. After Witherspoon declined to pose for photos at close range, police say Wallace became enraged and pushed a child out of the way, while hitting another with his camera, in his efforts to photograph the actress.