| Year | Title | Role | Notes | Refs |
| 1994 | Cybermania '94 | Himself (remote host) | Awards show | |
| 1999 | Sex and the City | Jack | Episode: "La Douleur Exquise!" | |
| The Mike O'Malley Show | Jimmy | 13 episodes | |
| 2000 | Third Watch | Kenny | Episode: "Spring Forward, Fall Back" | |
| 2001 | Boston Public | Hand Salesman | Episode: "Chapter Twenty-Nine" | |
| 2002 | Yes, Dear | Bobby | Episode: "Johnny Ampleseed" | |
| The Sopranos | Mike Waldrup | 2 episodes | |
| Law & Order: Special Victims Unit | Tony Damon | Episode: "Angels" | |
| 2003 | Undefeated | Scott Green's Assistant | Television film | |
| 2003–2006, 2013, 2018–2019 | Arrested Development | George Oscar "G.O.B." Bluth II | 82 episodes | |
| 2004 | Will & Grace | Artemis Johnson | Episode: "Back Up, Dancer" | |
| 2005 | Odd Job Jack | Tiberius McKorkindale | Voice, 2 episodes | |
| Danny Phantom | Ghost Writer | Voice, episode: "The Fright Before Christmas!" | |
| 2006 | Freak Show | Duncan Schiesst | Voice, 7 episodes | |
| O'Grady | Dougski | Voice, 1 episode | |
| The X's | Pork E. Bacon | Voice, episode: "From Crusha With Love" | |
| 2007 | King of the Hill | Portis | Voice, episode: "Hank Gets Dusted" | |
| 2007–2013 | 30 Rock | Devon Banks | 9 episodes | |
| 2008 | Sesame Street | Max the Magician | Episode: "Max the Magician" | |
| Human Giant | Himself | Episode: "I'm Gonna Live Forever!" | |
| 2009 | Sit Down, Shut Up | Ennis Hofftard | Voice, 13 episodes | |
| Delocated | TV Announcer | Voice, episode: "Good Buds" | |
| Monsters vs. Aliens: Mutant Pumpkins from Outer Space | The Missing Link | Voice, television film | |
| 2009–2011 | Late Night with Jimmy Fallon | Himself/Brett Favre | 6 episodes | |
| 2010 | Parks and Recreation | Chris | Episode: "The Set Up" | |
| 2010–2011 | Running Wilde | Steve Wilde | 13 episodes; also co-creator, writer, and executive producer | |
| 2010–2016 | The Increasingly Poor Decisions of Todd Margaret | Brent Wilts | 17 episodes | |
| 2011 | The Office | Fred Henry | Episode: "Search Committee" | |
| 2011–2012 | Up All Night | Chris | 35 episodes | |
| 2012 | The Cleveland Show | General Richter | Voice, episode: "A General Thanksgiving Episode" | |
| Comedy Bang! Bang! | Dale | Episode: "Seth Rogen Wears a Plaid Shirt & Brown Pants" | |
| 2013, 2015 | The Late Late Show | Himself (Guest host) | 3 episodes | |
| 2013–2014 | The Millers | Nathan Miller | 34 episodes | |
| 2014 | The Simpsons | Deputy Director Gratman | Voice, episode: "Steal This Episode" | |
| 2014–2020 | BoJack Horseman | BoJack Horseman / Additional voices | Voice, 76 episodes; also executive producer | |
| 2014 | Wander Over Yonder | Ryder | Voice, episode: "The Rider" | |
| 2016–2017 | Flaked | Chip | 14 episodes; also co-creator, writer, executive producer, and director | |
| 2016 | Unbreakable Kimmy Schmidt | Kitty | Voice; episode: "Kimmy Kidnaps Gretchen!"; uncredited | |
| 2017 | A Series of Unfortunate Events | Father/Mr. Quagmire | 8 episodes | |
| Jimmy Kimmel Live! | Himself (guest host) | 1 episode | |
| Minecon Earth 2017 | Himself (co-host) | YouTube live show | |
| Netflix: LIVE | Himself (host) | Netflix special | |
| 2017–2018 | The Gong Show | Himself (guest judge) | 5 episodes; also executive producer | |
| 2017 | The Magic School Bus Rides Again | Galapagos Gil | Voice, episode: "Frizzle Of The Future" | |
| 2017–2019 | Hot Date | Sam Keurig | Episode: "For Real, Where Have All My Friends Gone?"; also executive producer | |
| 2018 | The Guest Book | Rob | Episode: "Under Cover" | |
| 2019 | Unikitty! | Bruce Wayne / Batman / Batkitty | Voice, episode: "Batkitty" | |
| Riviera | Jeff Carter | 10 episodes | |
| 2020–present | LEGO Masters | Himself (host) | Also executive producer | |
