He was born in New York City to Audrey and Harvey Feuerstein, a teacher and lawyer, respectively. Mark celebrated his Bar Mitzvah at an Orthodox synagoge, and went to Princeton University for college. After college, he studied on a Fulbright scholarship at the London Academy of Music and Dramatic Art and L'Ecole Phillipe in France.
Feuerstein has acted in films and TV shows for almost twenty years. Among the movies he has acted in are What Women Want (1998), Rules of Engagement (2000), Defiance (2008) and In Your Eyes (2014). His television career includes roles on On the Lot (2007) and Royal Pains (a series that began in 2009).
In 2005, Feuerstein married TV writer and fellow Hollywood Jew, Dana Klein, and the couple has three children and lives in Los Angeles.