With his hangdog eyes and nerdy appeal, Knight instantly charmed viewers as a lovesick doctor on the wildly popular medical drama Grey's Anatomy. Prior to landing his seminal role, he was primarily a stage actor, honing his craft at the prestigious Guthrie Theater in his hometown of Minneapolis before moving to Broadway. Although he only had a handful of TV guest spots under his belt when he was cast on Grey's, he became one of the breakout stars of the hit series. In October 2006, he publicly acknowledged that he was gay; his announcement came a few days after his Grey's costar, Isaiah Washington, allegedly made a homophobic remark. Although the incident seemed to fade away, Washington stirred up bad blood again in January 2007 when he claimed that he hadn't called Knight a derogatory name during a post-Golden Globes press conference. Washington later retracted his denial but was subsequently fired at the end of the hit show's third season. In 2008, Knight asked producers to release him from his Grey's contract. His character, George O'Malley, died in the sixth-season premiere after being hit by a bus.
- Honed his craft in numerous productions staged by Minneapolis' Guthrie Theater, where he made his acting debut at age 5 as Tiny Tim in A Christmas Carol.
- Nominated for a Drama Desk Award for his role in the off-Broadway play Scattergood.
- Had a role in Charlie Lawrence, the Nathan Lane series that lasted only two episodes.
- Was a groomsman at the 2007 wedding of Grey's Anatomy costar Katherine Heigl.
- Considered one of his dream roles to be Mercutio in Romeo and Juliet and got the chance to play the role in a 2013 Off-Broadway production.
- 2007, Screen Actors Guild Awards — Outstanding Performance by an Ensemble in a Drama Series: Nominee
- 2007, Emmy — Outstanding Supporting Actor in a Drama Series: Nominee
- 2005, Screen Actors Guild Awards — Outstanding Performance by an Ensemble in a Drama Series: Nominee
- 2006, Screen Actors Guild Awards — Outstanding Performance by an Ensemble in a Drama Series: Winner
- Patrick — Husband
- Mark Cornelsen — Ex-significant Other
- Danny Knight — Brother
- Shirley Knight — Mother
- Birth Name: Theodore Raymond Knight
- Birth Place: Minneapolis, Minnesota, United States
- Profession: Actor