O'Hare won a Tony Award for Best Performance by a Featured Actor in a Play for his performance in Richard Greenberg's Take Me Out. He also won the 2005 Drama Desk Award for Outstanding Featured Actor in a Musical for his role as Oscar Lindquist in the Broadway revival of Sweet Charity. In 2004 he played Charles J. Guiteau in the Broadway production of Stephen Sondheim's Assassins, for which he was nominated for the Best Performance by a Featured Actor in a Musical Tony Award. He lost to co-star Michael Cerveris who played John Wilkes Booth. Before appearing in those shows, he appeared on Broadway in the 1998 revival of Cabaret, in which he played Ernst Ludwig onstage and the clarinet in the show's orchestra, the "Kit Kat Band." O'Hare was featured in the HallMark Hall of Fame presentation of Saint Maybe. He has appeared as a guest star on several episodes of Law & Order and its spin-offs, Law & Order: Special Victims Unit and Law & Order: Criminal Intent. In 2008, he has appeared as a guest star on several episodes of Brothers & Sisters. His feature film credits include The Anniversary Party, 21 Grams, Garden State, Derailed, Michael Clayton, A Mighty Heart, Half Nelson, and Milk and Charlie Wilson's War.
Mr. O'Hare portrays Phillip Steele (an amalgam character based on Quentin Crisp's friends Phillip Ward and Tom Steele) in the new television biopic on Quentin Crisp, titled An Englishman in New York, starring John Hurt and directed by Richard Laxton, produced by Amanda Jenks, and written by Brian Fillis. This spring, he is set to deput in An Iliad at Seattle Rep.
