| Year | Title | Role | Notes |
| 1992 | You Wrote It, You Watch It | Various | Series regular (also writer) |
| 1993–1995 | The State | Various | Series regular; 27 episodes (also co-creator & writer) |
| 1996 | Boston Common | Bob Cabot | Episode: "Gobble, Gobble, Aggch!" (2x09) |
| The Single Guy | Big Tipper | Episode: "The Deepest Cut" |
| 1997 | Spin City | Dan | Episode: "Bye Bye Love" (1x13) |
| Men Behaving Badly | Steve Cochrane | Series regular (season 2); 12 episodes |
| 1998 | Hercules | Tipis (voice) | Episode: "Hercules and the Argonauts" |
| 1998 | Holding the Baby | Mike | Episode: "Viva Las Gordy" |
| Conrad Bloom | Ben | Episode: "The Ultimatum" |
| 1999 | The Practice | Kevin Michaels | Episode: "End Games" (3x16) |
| Nash Bridges | Todd West | Episode: "Truth & Consequences" |
| 2000 | Angel | Wilson Christopher | Episode: "Expecting" (1x12) |
| Veronica's Closet | Wayne | Episode: "Veronica Sets Josh Up" (3x18) |
| Will & Grace | Mark | Episode: "Three's a Crowd, Six Is a Freak Show" (3x10) |
| 2001 | First Years | Miles Lawton | Series regular; 9 episodes (6 unaired) |
| 2001–2002 | Dawson's Creek | Professor David Wilder | Recurring guest star (season 5); 10 episodes |
| 2002 | Leap of Faith | Andy | 6 episodes |
| Haunted | Bob Pratt | Episode: "Fidelity" |
| Do Over | Reuben | Episode: "The Anniversary" |
| Charmed | Miles | Recurring guest star (season 5); 2 episodes |
| 2003 | Las Vegas | Anton McCarren | Episode: "Jokers and Fools" |
| 2003–2004 | Rock Me Baby | Kelly | 3 episodes |
| 2003–2022 | Reno 911! | Various | 5 episodes |
| 2004 | What I Like About You | Dr. Brad Turner | Recurring guest star (season 2); 3 episodes |
| Monk | Lester Highsmith | Episode: "Mr. Monk Takes His Medicine" |
| NYPD Blue | Det. Gerard Donnelly | Episode: "The 3-H Club" |
| 2005 | Inconceivable | Peter | Episode: "Sex, Lies and Sonograms" |
| Stella | Mr. Fabrizio | Episode: "Paper Route" (1x05) |
| 2005–2007, 2019 | Veronica Mars | Vinnie Van Lowe | Recurring; 13 episodes |
| 2006 | Falling in Love with the Girl Next Door | Mark Lucas | TV movie |
| Grey's Anatomy | Brad Ackles | Episode: "17 Seconds" (2x25) |
| 2007 | The Sarah Silverman Program | Patient | Episode: "Joan of Arf" |
| 2008 | CSI: Miami | Alan Farris | Episode: "You May Now Kill the Bride" |
| 2008–2009 | Reaper | Tony | Series regular; 9 episodes |
| 2008–2016 | Childrens Hospital | Dr. Glenn Richie/Just Falcon/Ron Donald/Glenn | Series regular; 69 episodes (also writer) |
| 2009 | United States of Tara | Mike Connor | Episode: "Possibility" |
| Greek | Camp Leader | Episode: "Take Me Home, Cyprus Rhodes" |
| In the Motherhood | Shep | 3 episodes |
| Private Practice | Mr. Larson | Episode: "The Way We Were" (3x02) |
| Californication | Professor David Wilder | Episode: "So Here's the Thing..." (3x07) |
| 2009–2010, 2023 | Party Down | Ronald Wayne "Ron" Donald | Series regular; 26 episodes (also director) |
| 2011–2013 | Whitney | Brian | 2 episodes |
| 2012 | Happy Endings | Richard "Rick" Rickman | Episode: "The Shrink, The Dare, Her Date and Her Brother" (2x10) |
| The Exes | Brad | Episode: "The Ex Always Rings Twice" (1x10) |
| Key and Peele | Dreadlocked Guy | Episode: "Flash Mob" |
| The League | Donny 'The Seed' Sedowsky | Episode: "The Tailgate" (4x06) |
| 2013 | Toy Story of Terror! | Pocketeer (voice) | TV short |
| Eastbound & Down | Guy Young | Recurring (season 4); 8 episodes |
| 2013–2019 | Drunk History | Various | 4 episodes |