Mark Hamlet was born in Rockville Centre, Long Island, New York. He grew up in Uniondale and moved to New York City in 1977. He attended Adelphi University in Garden City on a full-tuition drama scholarship, graduating with a B.A. in Theatre Arts.

In recent years, he’s been kicking around NYC on Theatre Row and various Greenwich Village venues, appearing in such plays as Sexual Psychobabble, Slap and Time It Is. He played the Archbishop of Canterbury for two seasons at the NY Renaissance Faire, and has several film credits including: (as Kirsten Dunst’s Father) Mona Lisa Smile, The Guru and Dead Canaries opposite Charles Durning. For twelve years he worked for Plays for Living, a theatre company specializing in social issue dramas for schools, churches and corporations nationwide.

In the summer of 2006, he had a leading role as Hank in Secrets, Off-Broadway at the St. Luke’s Theatre. In 2017 he played Leeson Carthage, Blair Brown's lawyer, on Orange Is the New Black. And he's had major roles in Momsters (as a detective) as well as Asockalypse! and Completely Normal, both available on Amazon. Watch for him in the upcoming theatrical film, Circle, as Dr. Cember.