Arkin has appeared in various television series such as Northern Exposure (CBS, 1990–95), where he played the eccentric chef Adam, and Chicago Hope (CBS, 1994–2000). He appeared in the Law & Order episode, Red Ball (Season 16, 2005),as a district attorney named Charles Graham. Other recent television appearances include The West Wing (1999) (as trauma specialist and psychologist Dr. Stanley Keyworth), Frasier, as an obsessive fan of Frasier's, Boston Legal, Baby Bob, Monk and 8 Simple Rules for Dating My Teenage Daughter (2002). As of 2007[update] he starred in the NBC drama Life in the role of Ted Earley. He plays a white separatist leader named Ethan Zobelle during the second season of the FX series Sons of Anarchy reuniting with former 8 Simple Rules cast mate Katey Sagal.

His film appearances include Hitch (2005) and Halloween H20: 20 Years Later (1998). Arkin is also a theatre actor where he has performed in Broadway, Off-Broadway and regional theatre productions, including most recently, both the South Coast Repertory world premiere and Broadway production of Brooklyn Boy by playwright Donald Margulies. In addition he is known for his directing work, having done episodes of Grey's Anatomy, Boston Legal, The Riches, Dirt and Ally McBeal. He won an Emmy for directing the Showtime television film My Louisiana Sky. In April 2008, Arkin guest-starred on the web series Gorgeous Tiny Chicken Machine Show. He recently played the part of a divorce lawyer in the film A Serious Man (2009) directed by Ethan and Joel Coen.

Arkin was born in Brooklyn, New York to actor/director/writer Alan Arkin and his wife Jeremy Yaffe. He has been married to the former Phyllis Anne Lyons since 1999. They have one son together. He also has a daughter, Molly, from his former wife, Linda.