Frank Vlastnik (born May 30, 1969 in Peru, Illinois) is an American theatre and television actor. He is best known as an original cast member in the short lived musicals Big, The Sweet Smell of Success, and A Year with Frog and Toad on Broadway. His big break came when he was cast as the original understudy for the leading role in Big. He later starred on and off-Broadway in A Year with Frog and Toad in which he played all the male secondary characters and was featured on the cast album. He also guest starred on an episode of Law & Order.