At 37 years old, Olivia Thirlby has this physical status:
While still in high school, Thirlby was offered a role in The Secret. In 2006, she made her film debut in United 93 and her television debut in Kidnapped.
In 2007, she played Leah in Juno. Around this time, she and her Juno co-star Elliot Page were slated to star as the respective title characters of Jack & Diane as two young women who fall in love which unlocked lycanthropy in one character but both dropped out before production, and the cast was replaced numerous times over. She plays Stephanie, a marijuana-smoking "popular girl" from New York City, in Sundance Audience Award-winning mid-1990s period piece film The Wackness, which was released in the U.S. on July 3, 2008, and stars opposite Josh Peck. Thirlby was cast in the Judd Apatow-produced, David Gordon Green-directed stoner comedy Pineapple Express as the girlfriend of Seth Rogen's character, but was replaced by Amber Heard after rehearsing for the film. She reunited with David Gordon Green on the animated TV pilot Good Vibes.
She made her stage debut in Farragut North, a play by Beau Willimon at the Atlantic Theater Company in New York City. The Off-Broadway production ran from October 22, 2008 – November 29, 2008 with official opening on November 12 and transferred to the Geffen Playhouse in June 2009.
Thirlby appeared in the 2009 HBO series Bored to Death. She voices promotional video excerpts from the novel Thirteen Reasons Why by Jay Asher which, since October 2008, have regularly been posted to YouTube. She also appeared in the 2011-released film Margaret. She was attached to star in Christmas in New York, though the film was not made, as well as For Ellen, where it appears she did not accept a role.
Thirlby starred in the Russian science-fiction film The Darkest Hour, released in 2011, directed by Chris Gorak, and produced by Timur Bekmambetov. Thirlby was also cast in the lead role of Max in the upcoming drama comedy The Other Side.
Thirlby starred as Judge Cassandra Anderson in the 2012 film adaptation of Judge Dredd, with Karl Urban in the title role. She next starred in the indie film Nobody Walks co-starring John Krasinski and Rosemarie DeWitt. She plays Martine, a young artist taken in a couple's home. It premiered at 2012 Sundance Film Festival. In 2016, Thirlby co-starred as the young attorney Lucy Kittridge in the Amazon Studios legal series Goliath. 2017 saw her play a main character in the thriller Damascus Cover. In 2018 she took the lead in The White Orchid. She also portrayed the main character in 2019's Above the Shadows. Thirlby featured as MCC minister Rebecca Dowery in the 2019 Showtime drama series The L Word: Generation Q. She was Hero Brown, a main character in 2021's Y: The Last Man.