
As an actor, Mark Blum has appeared on Broadway in Twelve Angry Men, The Graduate, A Thousand Clowns, Gore Vidal's The Best Man, Lost In Yonkers, My Thing of Love, and The Merchant. Off-Broadway appearances include We Live Here, Picked, After The Revolution, The Singing Forest, Mourning Becomes Electra, The Long Christmas Ride Home, The Waverly Gallery, Mizlanski Zilinski, Little Footsteps, It's Only A Play, Gus and Al (for which he was awarded an Obie), Key Exchange, Table Settings, and Say Goodnight Gracie.
His films include I Don’t Know How She Does It, Shattered Glass, Desperately Seeking Susan, Crocodile Dundee, The Presidio, Blind Date, Worth Winning, Lovesick, and Miami Rhapsody.
On TV, he has appeared in the HBO movie Indictment: The McMartin Trial, the Showtime movie The Defenders, the NBC mini-series The Judge, and the CBS Jesse Stone Mystery, Innocents Lost. He has been a regular on Capital News and Sweet Surrender, and made guest appearances on, among others, Mercy, Fringe, The Sopranos, The West Wing, Law and Order, Law and Order Criminal Intent, Law and Order SVU, CSI Miami, NYPD Blue, Frasier, The Practice, Judging Amy, Roseanne, Wings, Miami Vice, and St. Elsewhere.
He has written several screenplays, rewritten several others, and has produced the independent films Search and Destroy, and The Lowlife. He teaches at the HB Studio, Primary Stages, at Fordham University, and in the graduate training program at Brooklyn College. He has also taught at Manhattan School of Music, Manhattan Theater Club, and Lincoln Center. He holds a Bachelor of Arts degree in Theater from the University of Pennsylvania, and an MFA in Acting from the University of Minnesota.