In 1988, Malloy began his acting career in earnest appearing in the made-for-television movie, The Caine Mutiny Court-Martial, followed by the HBO mockumentary TV series, Tanner '88, as New York City filmmaker, Deke Conners.
In 1989, Malloy appeared in his first box office movie role as the bum Otis in The Unbelievable Truth.
Malloy was born in the village of Hamilton, New York. He graduated from State University of New York at Purchase. In the 2012 documentary, That Guy... Who Was in That Thing, Malloy stated that his uncle, actor Henry Gibson, inspired him to pursue an acting career. Malloy is married to Director and Producer Cas Donovan.
From 2013 to 2014, Malloy starred as Nevada Senator Louis Laffer in Amazon's Alpha House, a political comedy written by Doonesbury creator Garry Trudeau. Along with John Goodman, Malloy played one of four Republican senators living in a house on Capitol Hill.
