Gregory Martin Itzin (born April 20, 1948 Washington, District of Columbia, USA) is an Emmy nominated American film and television actor.
Itzin has appeared in guest starring roles on various television shows like in "MacGyver" Final Approach (TV Episode 1986). His most recent major role has been President Charles Logan on the popular television drama 24. He received a Tony Award nomination for his role in the Pulitzer Prize–winning play The Kentucky Cycle. In the movie Airplane!, Itzin plays Religious Zealot #1, and has the first lines in the movie, but disappears after the first scene. He had a short role in The A-Team episode 'Wheel of Fortune', as accountant Howard for a casino-owner.
Itzin has held recurring roles on popular TV series such as Friends as Theodore Hannigan, father of Mike Hannigan, Murder One, NCIS, and The Mentalist. He played the head of the unit in the latter for 13 episodes, before leaving to return to 24 for its final season. Itzin also appeared on Night Court, Matlock, Diagnosis: Murder, Jake and the Fatman, The O.C., Beverly Hills, 90210, Judging Amy, Boston Legal, CSI: Crime Scene Investigation, The Practice, The Pretender and the short-lived science fiction series, Firefly. He also portrayed John Ashcroft in the 2003 television movie DC 9/11: Time of Crisis. He had a recurring role on Covert Affairs.
He is also a frequent Star Trek actor, having played five different roles in the various series over the years; his most recent Trek role was Admiral Black in Star Trek: Enterprise. He made his first Star Trek appearance in 1993, in the Star Trek: Deep Space Nine episode "Dax". He later guest starred on DS9 again, in the sixth-season episode "Who Mourns for Morn?". He also appeared as Doctor Dysek in the episode "Critical Care" in the 7th season of Star Trek: Voyager.
