Filmography32 titles
| Year | Title | Character | Age at release |
|---|---|---|---|
| 2023 | LEGENDSeries | — | 73 |
| 2011 | Fairly LegalSeries | David Smith | 61 |
| 2010 | Raising HopeSeries | Keith | 60 |
| 2009 | Stargate UniverseSeries | Jack O'Neill | 59 |
| 2009 | Stargate SG-1: Children of the GodsMovie | Colonel Jack O'Neill | 59 |
| 2008 | Stargate: ContinuumMovie | Major General Jack O'Neill | 58 |
| 2004 | Stargate AtlantisSeries | Jack O'Neill | 54 |
| 1997 | Stargate SG-1Series | Jack O'Neill | 47 |
| 1996 | Pandora's ClockSeries | James Holland | 46 |
| 1996 | FirehouseMovie | Lt. Michael Brooks | 46 |
| 1995 | Past the BleachersMovie | Bill Parish | 45 |
| 1995 | LegendSeries | Ernest Pratt / Nicodemus Legend | 45 |
| 1994 | MacGyver: Lost Treasure of AtlantisMovie | MacGyver | 44 |
| 1994 | MacGyver: Trail to DoomsdayMovie | Angus MacGyver | 44 |
| 1994 | Beyond BetrayalMovie | Bradley | 44 |
| 1994 | Beyond BetrayalMovie | Bradley Matthews | 44 |
| 1992 | In the Eyes of a StrangerMovie | Jack Rourke | 42 |
| 1989 | The SimpsonsSeries | Richard Dean Anderson (voice) | 39 |
| 1988 | The World's Greatest Stunts: A Tribute to Hollywood StuntmenMovie | Self (archive footage) | 38 |
| 1986 | Odd JobsMovie | Spud | 36 |
| 1986 | Ordinary HeroesMovie | Tony Kaiser | 36 |
| 1985 | MacGyverSeries | Angus MacGyver | 35 |
| 1983 | Emerald Point N.A.S.Series | Navy Lt. Simon Adams | 33 |
| 1982 | Young Doctors in LoveMovie | Drug dealer | 32 |
| 1982 | Seven Brides for Seven BrothersSeries | Adam McFadden | 32 |
| 1981 | Entertainment TonightSeries | Self | 31 |
| 1979 | The Facts of LifeSeries | — | 29 |
| 1977 | The Love BoatSeries | Carter Randall | 27 |
| 1976 | Battle of the Network StarsSeries | — | 26 |
| 1975 | Saturday Night LiveSeries | Self - Cameo (uncredited) | 25 |
| 1962 | The Tonight Show Starring Johnny CarsonSeries | Self | 12 |
| 1944 | Golden Globe AwardsSeries | Self - Presenter | — |