Larson was born in Sacramento, California. Her parents were chiropractors who ran a practice together. Her parents separated during her childhood, and she moved to Los Angeles, with her mother and younger sister, Milaine. Growing up, Larson’s first language was French.[4] Brie stated in an interview with Glamour that she chose “Larson” as her stage name from her great-grandmother’s maiden name, as her surname was too difficult to pronounce. She later claimed on The Tonight Show with Jimmy Fallon that her choice was influenced by an American Girl doll she received as a child.

Acting Career_________________________Larson’s first job was performing in sketches on The Tonight Show with Jay Leno. Soon after, she was cast in the television series Schimmel, which never aired because its star, Robert Schimmel, was diagnosed with cancer shortly before filming was to begin. After it was “on hold” for ten months, Fox canceled the show. Larson later auditioned for a new show for The WB called In Your Dreams, and landed the role of Bob Saget’s character’s younger daughter, Emily. The show was selected for the 2001–02 fall season, and was renamed Raising Dad. It was then canceled after 27 episodes. Larson was also cast in the pilot for the ABC sitcom Hope & Faith, but she and some other cast members were dropped after the unaired pilot.

In 2003, she starred alongside Beverley Mitchell on the Disney Channel original movie Right on Track. In July 2004, she co-starred with a large cast of teen actors in the film Sleepover. She also had a small role in the movie 13 Going on 30. Larson appeared in the 2006 film Hoot, opposite actors Logan Lerman and Cody Linley. Her voice is also featured in the film Farce of the Penguins as a teenage penguin. She played Angie in the 2007 comedy-drama Remember the Daze and also appeared in the 2008 short film The Babysitter, written and directed by David H. Steinberg. She appeared in an episode of Ghost Whisperer in January 2008. She also has a role as Kate in the 2008 film, Tanner Hall, directed by Francesca Gregorini and Tatiana von Fürstenberg. Larson played the character Kate Gregson on the Showtime series United States of Tara. The show premiered on January 18, 2009 and was not renewed after its third season. The season finale aired on June 20, 2011.

In 2012, Larson played Molly in the film adaptation of the popular 1980s TV show 21 Jump Street, co-starring with Jonah Hill and Channing Tatum. In 2013, she guest-starred as Rachel in an episode of Community titled “Herstory of Dance”, and again in the episode “Analysis of Cork-Based Networking” the following year. In 2013, she also starred in Short Term 12. She appeared as a guest on The Late Late Show with Craig Ferguson several times between 2010 and 2013.

In 2015, Larson played the sister of Amy Schumer’s character in the film Trainwreck. She also starred in Room, a film adapted from the novel of the same name by Emma Donoghue. The film played at the Toronto International Film Festival, and began its theatrical release on October 16, 2015. It has received widespread critical acclaim, particularly for Larson’s performance.

Larson has been cast in Kong: Skull Island, cast along with Samuel L. Jackson and Tom Hiddleston.

Music Career_________________________Larson has launched a career as a musician, singer and songwriter, and after releasing her debut album in a major record label in 2005, and has been performing in live concerts throughout the United States since then. A second album came to production and was completed but never released. Most recently, Larson revealed plans to release an EP, but that also never reached the public. She did not give up on her career as a musician, but it is not known when she will release new songs. Her last public appearance as a singer was in 2010, when she performed “Black Sheep”, along with the band Metric in the movie Scott Pilgrim vs. the World.

Her interest in being a singer started in early 2003, when she began to promote her songs through her personal website and was already showing interest in releasing an album. The first leaked was “Go Goodbye”, a song about “two great people who just aren’t great together”, in her own words and along with “Invisible Girl”, were the tracks that led Larson to sign a record deal some time after with Casablanca Records, a Universal Records imprint. Both songs were produced and written with the help of Michael Binikos and Craig Bartock. In 2003, she leaked another track, “Not a Freak” and this time there was even a music video for it, which was available for purchase online. In late spring of 2004, she removed all the songs on her website due to Casablanca’s contract restrictions and was in the process of recording new songs for her first album.

In October of that same year, her willingness to release an album was coming closer and “She Said”, the first single from her yet-to-be-released debut album at that time was available to listen via her official website gaining an official release in iTunes in December and was sent to radios across the country in the following month. Despite having been the 99th best-selling CD single in the country in 2005, according to SoundScan and peaking at number 31 on the Billboard Hot 100 Single Sales, the song failed to reach the Top 40 of the most played songs in the country, receiving low airplay. She also recorded live performances for AOL Sessions on October 11, 2004.

Her only released album, Finally Out of P.E., went on sale in late 2005 and sold 3,500 copies in U.S. Before its release, her record label released a DVD featuring “She Said” music video, the making of it and her AOL Sessions performances. The entire album was focused in teenage audiences and that became clear while she was playing in Teen People’s Rock in Shop Tour, went on tour with Jesse McCartney and received a lot of airplay from children-oriented radios like Radio Disney and Radio KOL. The music video for “She Said”, directed by Chris Applebaum, showed a story about a bored fast food restaurant worker who was aiming to sing and, that way, “finding herself”. She also sang “Hope Has Wings”, the song from the credits of the movie Barbie and the Magic of Pegasus. A music video for the song appears as a bonus feature on the movie’s DVD.

In 2006, she recorded a song slightly different from her previous works for the soundtrack of the Hoot movie, “Coming Around”, co-written with Jacques Brautbar and Rami Perlman, vocalist and guitarist of a Los Angeles-based independent band. On March 1, 2006, Larson performed an acoustic set of new songs at L.A.’s famous Viper Room. The songs played were “Dear Universe”, “Powershift”, “Stilts and the Titanic”, “Superstition”, a cover of Indigo Girls’ “Closer to Fine” and “Falling Into History”, a track from her album. From the new songs, the only one to be leaked in a studio recording was “Stilts and the Titanic”, produced and co-written by Binikos. The song was made available to listen and download as a demo version in Larson’s Official Myspace in the summer 2006. On October 22, 2008 she announced to fans in a blog published in her official Myspace page that she will be recording a 5 track EP with new material and will provide backing vocals for artist Caitlin Crosby’s latest album. The EP was to include a re-recorded version of Ugly (a track from her album) and four new songs: “Dear Universe”, “Sharpen My Nails”, “Arielle”, and “If All Goes Well”.