| Year | Title | Role | Notes |
| 1979 | Studs Lonigan | Bill 'Studs' Lonigan | 3 episodes |
| 1984 | Master of the Game | Anthony James 'Tony' Blackwell | 3 episodes |
| 1985 | Space | John Pope | 5 episodes |
| 1986–91 | Law | Michael Kuzak | 102 episodes |
| 1988 | Favorite Son | Senator Terry Fallon | Episode: "Part One" |
| 1992 | Batman: The Animated Series | Anthony Romulus, Cameron Kaiser | Voice, 2 episodes |
| 1992 | The Legend of Prince Valiant | Sir Lymon | Voice, episode: "The Traitor" |
| 1997 | Ink | Brian | 4 episodes |
| 1997 | The Nanny | Professor Steve | Episode: "Educating Fran" |
| 1998 | The Outer Limits | Ford Maddox | Episode: "Monster' |
| 1999–2000 | Movie Stars | Reese Hardin | 21 episodes |
| 2001 | Touched by an Angel | Liam | Episode: "Winners, Losers & Leftovers" |
| 2004–06 | Veronica Mars | Aaron Echolls | 12 episodes |
| 2005 | Arrested Development | Himself | Episode: "For British Eyes Only" |
| 2007 | Law & Order | Randall Bailey | Episode: "The Family Hour" |
| 2009 | Harper's Island | Uncle Marty Dunn | 2 episodes |
| 2010–11 | Army Wives | Professor Chandler | 8 episodes |
| 2010 | Harry Loves Lisa | Himself | 2 episodes |
| 2011 | Curb Your Enthusiasm | Dino | Episode: "The Smiley Face" |
| 2011 | Franklin & Bash | Rick Paxton | Episode: "Bro-Bono" |
| 2012–14 | Shameless | Lloyd "Ned" Lishman | 8 episodes |
| 2013–14 | Mad Men | Jim Cutler | 15 episodes |
| 2014 | Rush | Dr. Warren Rush | 4 episodes |
| 2014–15 | Law & Order: Special Victims Unit | Chief Charles Patton | 2 episodes |
| 2014–22 | The Real Housewives of Beverly Hills | Himself | Appearing as Lisa Rinna's husband (guest) |
| 2015 | Glee | Walter | 4 episodes |
| 2016 | Mom | Fred Hayes | 2 episodes |
| 2016–17 | Graves | Jonathan Dalton | 5 episodes |
| 2017–18 | Shooter | Addison Hayes | 3 episodes |
| 2017 | Law & Order True Crime | Barry Levin | 2 episodes |
| 2018 | Angie Tribeca | Leonard Scholls | Episode: "Heading to the Legal Beagle" |
| 2021 | Bless the Harts | Rod | Voice, episode: "Hot Tub-Tation" |
| 2021 | The Hot Zone: Anthrax | Tom Brokaw | 2 episodes |
| 2022 | Flowers in the Attic: The Origin | Mr. Winfield | Episode: "Part One: The Marriage" |
| 2023–present | Mayfair Witches | Cortland Mayfair | Main role |
