Filmography83 titles
Importing filmography…
| Year | Title | Character | Age at release |
|---|---|---|---|
| 2023 | Babylon 5: The Road HomeMovie | Lennier (voice) | 69 |
| 2018 | Lost in SpaceSeries | Dr. Zachary Smith | 64 |
| 2018 | What We Left Behind: Looking Back at Star Trek: Deep Space NineMovie | Self | 64 |
| 2016 | The Loud HouseSeries | Timothy Mccole | 62 |
| 2012 | Bravest WarriorsSeries | Ralph Waldo Pickle Chips | 58 |
| 2010 | Ben 10: Ultimate AlienSeries | Agent Bryson (voice) | 56 |
| 2009 | The Face is FamiliarMovie | Narrator | 55 |
| 2006 | Look, Up in the Sky! The Amazing Story of SupermanMovie | Self | 52 |
| 2006 | Holly Hobbie and Friends: Christmas WishesMovie | Bud Morris / Judge #1 (voice) | 52 |
| 2005 | DerailroadedMovie | Self | 51 |
| 2005 | Ringers: Lord of the FansMovie | Self | 51 |
| 2002 | The Twilight ZoneSeries | Anthony Fremont | 48 |
| 2002 | What's New, Scooby-Doo?Series | Harry Noze (voice) | 48 |
| 2002 | Larry 'Wild Man' FischerMovie | Self | 48 |
| 2001 | Crossing JordanSeries | Paper Shredder Operator | 47 |
| 2000 | Buzz Lightyear of Star CommandSeries | Eon (voice) | 46 |
| 2000 | Behind the DementiaMovie | himself | 46 |
| 1999 | Attack of the 50 Foot Monster ManiaMovie | Narrator | 45 |
| 1998 | Lost In Space ForeverMovie | Self (also archive footage) | 44 |
| 1997 | The Weird Al ShowSeries | — | 43 |
| 1996 | Space CasesSeries | — | 42 |
| 1996 | The Monkey PrinceMovie | Sam (voice) | 42 |
| 1996 | Underground AdventureMovie | Sam (voice) | 42 |
| 1995 | Three WishesMovie | Neighbor | 41 |
| 1995 | The Fantasy Worlds of Irwin AllenMovie | Self - Host | 41 |
| 1994 | Space Ghost Coast to CoastSeries | — | 40 |
| 1994 | Babylon 5Series | Lennier | 40 |
| 1994 | A Bewitched ChristmasMovie | Michael (as Billy Mumy) | 40 |
| 1994 | The Steven Banks ShowSeries | Billy Mumy | 40 |
| 1993 | Diagnosis: MurderSeries | Parker Craddick | 39 |
| 1993 | Star Trek: Deep Space NineSeries | Kellin | 39 |
| 1993 | AnimaniacsSeries | The Farmer (voice) | 39 |
| 1992 | Batman: The Animated SeriesSeries | The Fox (voice) | 38 |
| 1992 | Double TroubleMovie | Bob | 38 |
| 1990 | The FlashSeries | Roger Braintree | 36 |
| 1990 | Captain AmericaMovie | Young General Fleming | 36 |
| 1988 | SuperboySeries | — | 34 |
| 1987 | ZabagabeeMovie | Art Barnes | 33 |
| 1986 | MatlockSeries | Dr. Irwin Bruckner | 32 |
| 1984 | Hard to HoldMovie | The James Roberts Band - Keyboard | 30 |
| 1983 | Twilight Zone: The MovieMovie | Tim | 29 |
| 1980 | Fish HeadsMovie | — | 26 |
| 1977 | Sunshine ChristmasMovie | Weaver | 23 |
| 1976 | ArchieMovie | Larry | 22 |
| 1975 | Saturday Night LiveSeries | Art Barnes (uncredited) | 21 |
| 1975 | SunshineSeries | Weaver | 21 |
| 1974 | The Rockford FilesSeries | Trask | 20 |
| 1974 | The Rockford Files: Backlash of the HunterMovie | Nick Butler | 20 |
| 1973 | PapillonMovie | Lariot | 19 |
| 1973 | SunshineMovie | Weaver | 19 |
| 1971 | Bless the Beasts & ChildrenMovie | Lawrence Teft | 17 |
| 1969 | RascalMovie | Sterling North | 15 |
| 1968 | LancerSeries | — | 14 |
| 1968 | Wild in the StreetsMovie | Boy (uncredited) | 14 |
| 1965 | Lost in SpaceSeries | Will Robinson | 11 |
| 1965 | I Dream of JeannieSeries | Custer | 11 |
| 1965 | Lost in Space - No Place to HideMovie | Will Robinson | 11 |
| 1965 | Dear BrigitteMovie | Erasmus 'Ras' Leaf | 11 |
| 1964 | BewitchedSeries | Michael | 10 |
| 1964 | The MunstersSeries | — | 10 |
| 1963 | The FugitiveSeries | David Taft | 9 |
| 1963 | The Greatest Show on EarthSeries | Jeff | 9 |
| 1963 | Vacation PlayhouseSeries | Chris Williams | 9 |
| 1963 | A Child Is WaitingMovie | Child | 9 |
| 1963 | Palm Springs WeekendMovie | Boom Boom Yates | 9 |
| 1962 | The VirginianSeries | Willy | 8 |
| 1962 | The Alfred Hitchcock HourSeries | Tony Mitchell | 8 |
| 1962 | Going My WaySeries | — | 8 |
| 1961 | Ben CaseySeries | — | 7 |
| 1961 | Dr. KildareSeries | Jeffey | 7 |
| 1961 | Kraft Mystery TheatreSeries | — | 7 |
| 1961 | Tammy Tell Me TrueMovie | Neil Bateman | 7 |
| 1961 | The Wizard of BaghdadMovie | Aladdin | 7 |
| 1960 | National VelvetSeries | — | 6 |
| 1959 | The Twilight ZoneSeries | Young Pip | 5 |
| 1957 | Wagon TrainSeries | Toddy | 3 |
| 1957 | Perry MasonSeries | Miles | 3 |
| 1957 | Have Gun, Will TravelSeries | Little Boy at Carlton Hotel | 3 |
| 1955 | Alfred Hitchcock PresentsSeries | Jackie Chester | 1 |
| 1954 | The Wonderful World of DisneySeries | Petey Loomis | — |
| 1953 | General Electric TheaterSeries | Buzz | — |
| 1953 | Letter to LorettaSeries | Rennie | — |
| 1950 | The Jack Benny ProgramSeries | Little Boy Who Weighs Himself | — |