T.R. Knight first got involved in acting at age 5, when he joined the Guthrie Theater in Minneapolis. As a high school freshman, he received a scholarship from the Connors Foundation, enabling him to train further in acting. He briefly attended the University of Minnesota but dropped out to pursue an acting career, landing leading roles at the Guthrie, appearing until 2001.
Knight made his Broadway debut in 2001, in a revival of Noises Off. He went on to appear in several Broadway and off-Broadway stagings, notably Scattergood, for which he earned a Drama Desk Award nomination in 2003.
Knight's biggest break came in 2005, when he joined the cast of the ABC medical drama Grey's Anatomy. His portrayal of conflicted intern George O'Malley earned him an Emmy nomination in 2007. However, his stay on the show was marred by a very public confrontation with co-star Isaiah Washington, where the latter insulted Knight's sexual orientation.
Knight left Grey's Anatomy at the end of the fifth season, after which he returned to stage, most recently in a staging of David Mamet's A Life in the Theatre.
- He is best friends with his Grey's Anatomy co-star Katherine Heigl who also plays his best friend on screen.
- Screen Actors Guild Award, Outstanding Performance by an Ensemble in a Drama Series, 2007 (for Grey's Anatomy)
- Threads (2002)
- The Last Request (2006)
- Charlie Lawrence (regular, 2003)
- Grey's Anatomy (regular, 2005-2009)
"I guess there have been a few questions about my sexuality, and I'd like to quiet any unnecessary rumors that may be out there. While I prefer to keep my personal life private, I hope the fact that I'm gay isn't the most interesting part of me."