- Began acting in summer stock at age 12, making his stage debut as the Artful Dodger in a New Jersey production of Oliver!
- Made Broadway debut in 1986 as a replacement in the role of Eugene Jerome in Neil Simon's Brighton Beach Memoirs.
- Breakthrough movie role was as sensitive student Neil Perry in 1989's Dead Poets Society.
- Best known as oncologist James Wilson on FOX's medical drama House, a role he has played since 2004.
- 2001, Tony — Actor (Featured Role--Play): Winner
- 2003, Tony — Actor (Featured Role--Play): Nominee
- 1993, Tony — Actor (Featured Role--Play): Nominee
- 2008, Screen Actors Guild Awards — Outstanding Performance by an Ensemble in a Drama Series: Nominee
- Gabriella Salick — Wife
- Robert Howard Leonard — Father
- Sean Robert Leonard — Brother
- Gwyneth Paltrow — Ex-significant Other
- Kimberly Leonard — Sister
- Joy Leonard — Mother
- Attended Columbia University, New York, NY
- Birth Name: Robert Lawrence Leonard
- Birth Place: Westwood, NJ
- Birthday: February 28, 1969, Pisces
- Profession: Actor