A native New Yorker, Callen graduated from American University before pursuing a career as a comedian. After getting his comedy start at the renowned Comic Strip in New York, Callen performed for years in comedy clubs throughout New York and Los Angeles. His televised stand-up performances include an appearance on The Late Show with David Letterman. Callen made his television debut on Mad TV, where he created several characters including Pool Boy and the Octeroon. His numerous television guest-starring appearances include Oz and NBC's Frasier and Suddenly Susan. Callen's feature film credits include Kiss and Tell and Jack and Jill, which was a winner at the Hamptons Film Festival. He enjoys karate, boxing, wrestling and fencing. He currently resides in Venice, California.