Robert Sean Leonard

Leonard is a three-time Tony Award nominee, and won Best Featured Actor in a Play in 2001 for his role as A. E. Housman in Tom Stoppard's The Invention of Love. He had previously played the role of Valentine in the New York premiere of Stoppard's Arcadia at Lincoln Center in 1995. He was nominated for a Tony in 2003 for his portrayal of Edmund Tyrone in a well-received revival of Eugene O'Neill's Long Day's Journey Into Night, co-starring Philip Seymour Hoffman, Brian Dennehy, and Vanessa Redgrave. He has also appeared in Broadway musical productions, and replaced Craig Bierko as the lead performer in a revival of The Music Man in 2001. He co-starred as Paul Verrall in the 2011 Broadway revival of Born Yesterday.

Leonard and Ethan Hawke co-founded New York's Malaparte theater company alongside James Waterston, Steve Zahn, and Frank Whaley in 1991. The company was officially dissolved in 2000.

Leonard's early film roles included The Manhattan Project (1986), My Best Friend Is a Vampire (1987), and Dead Poets Society (1989). In 1993, he had a leading role in the film Swing Kids, playing Peter Müller, appeared in the Shakespeare film adaptation Much Ado About Nothing, and appeared in Martin Scorsese's The Age of Innocence. In 1997, he received rave reviews for his role in the television film In the Gloaming, directed by Christopher Reeve.

From 2004 to 2012, Leonard had his most famous onscreen role as Dr. James Wilson in the Fox medical drama series House. From 2013 to 2014, Leonard had a recurring role as Dr. Roger Kadar on the series Falling Skies. In 2016, he played King Arthur in David Lee's adaptation of the musical Camelot at the Westport Country Playhouse. From February to April 2017, he appeared in the Broadway revival of Sunday in the Park with George as Jules/Bob. In 2023, he had a supporting role in HBO's The Gilded Age as the Reverend Luke Forte.