Thomas Cavanagh was born on October 26th, 1963 in Ottawa, Ontario, the second-oldest of five children. His close-knit family moved to Ghana, Africa when Tom was six. His father educated teachers there. The family moved back to Canada before Tom started high school (which he attended in southern Quebec). Tom went to Queens University in Kingston, Ontario where he played on the basketball team and graduated with degrees in English, Biology, and Education. His interest in theater grew when he was cast as the lead Danny Zuko in a Canadian "Grease". Since then, he has been in a moderate amount of movies, but is gaining popularity for his starring, award-winning role on the new NBC series Ed (2000), in which he plays the lovable, charming Ed Stevens. Cavanagh resides in L.A., where he has lived for two years. In his spare time he likes to play guitar and participate in a variety of sports.
| Movie | Don't Move | 2026 | |
| Movie | Bitcon | Beam | 2022-10-18 |
| Movie | Love & Debt | Henry Warner | 2019-09-21 |
| Movie | Jay and Silent Bob Reboot | 2019-10-15 | |
| Movie | Darrow & Darrow: In The Key Of Murder | Miles | 2018-05-06 |
| Movie | Darrow & Darrow: Body of Evidence | Miles | 2018-10-14 |
| Movie | Tom and Grant | Tom | 2018-07-21 |
| Movie | Darrow & Darrow | Miles | 2017-10-22 |
| Movie | Sidekick | Darkman | 2016-10-28 |
| Series | DC's Legends of Tomorrow | Harrison Wells | 2016-01-21 |
| Movie | 400 Days | Zell | 2015-10-29 |
| Series | Supergirl | Harrison Wells | 2015-10-26 |
| Movie | Lucky Duck | Snap (voice) | 2014-06-06 |
| Series | The Flash | Harrison Wells | 2014-10-07 |
| Movie | The Games Maker | Mr. Drago | 2014-07-03 |
| Movie | The Birder | Ron Spencer | 2013-10-06 |
| Series | The Following | Kingston Tanner | 2013-01-21 |
| Series | Arrow | Dark Flash | 2012-10-10 |
| Movie | A Killer Among Us | Nick Carleton | 2012-09-08 |
| Movie | Trading Christmas | Charles Johnson | 2011-11-26 |
| Movie | Edgar Floats | Edgar Floats | 2010-01-01 |
| Movie | Yogi Bear | Ranger Smith | 2010-12-17 |
| Series | Blue Bloods | Mickey | 2010-09-24 |
| Movie | Snow 2: Brain Freeze | Nick Snowden | 2009-12-05 |
| Series | Trust Me | Conner | 2009-01-26 |
| Series | Eli Stone | Unknown | 2008-01-31 |
| Series | The Capture of the Green River Killer | Dave Reichert | 2008-03-30 |
| Movie | Bob & Doug McKenzie's Two-Four Anniversary | Self | 2007-05-20 |
| Movie | Gray Matters | Sam Baldwin | 2007-02-23 |
| Movie | The Cake Eaters | Lloyd | 2007-04-29 |
| Movie | Breakfast with Scot | Eric McNally | 2007-11-16 |
| Movie | Sublime | George Grieves | 2007-06-15 |
| Series | Stories from the Vaults | Himself - Host | 2007-09-03 |
| Series | Love Monkey | Tom Ferrell | 2006-01-17 |
| Movie | How to Eat Fried Worms | Dad | 2006-08-25 |
| Movie | Two Weeks | Barry Bergman | 2006-10-20 |
| Movie | Alchemy | Mal Downey | 2005-04-25 |
| Series | Jack & Bobby | 2004-09-12 | |
| Movie | Heart of the Storm | Simpson | 2004-11-22 |
| Movie | Snow | Nick Snowden | 2004-12-13 |
| Series | The Tony Danza Show | 2004-09-13 | |
| Movie | Bang Bang You're Dead | Val Duncan | 2003-06-11 |
| Series | Scrubs | Dan Dorian | 2001-10-02 |
| Movie | Something More | Harry | 2000-11-28 |
| Series | Ed | Ed Stevens | 2000-10-08 |
| Series | Providence | Unknown | 1999-01-08 |
| Movie | Anya's Bell | Patrick Birmingham | 1999-10-31 |
| Series | Sports Night | Unknown | 1998-09-22 |
| Movie | Northern Lights | Frank | 1998-07-02 |
| Series | Cold Squad | Unknown | 1998-01-23 |
| Series | The View | Unknown | 1997-08-11 |
| Movie | Honeymoon | Jamie | 1997-01-01 |
| Movie | Bloodhounds II | Levesh | 1996-01-26 |
| Movie | Mask of Death | Joey | 1996-05-25 |
| Movie | Profile for Murder | Tim Jonas | 1996-08-24 |
| Series | The Daily Show | Unknown | 1996-07-22 |
| Movie | Dangerous Intentions | Ron | 1995-01-03 |
| Movie | Magic in the Water | Simon, Patient #1 | 1995-08-30 |
| Series | The Outer Limits | Unknown | 1995-03-26 |
| Series | Late Night with Conan O'Brien | Unknown | 1993-09-13 |
| Movie | Other Women's Children | Marco | 1993-10-24 |
| Series | LIVE with Kelly and Mark | Unknown | 1988-09-05 |