Film

No.	Year	Title	Role	Vote Average
1	1961	The Wizard of Baghdad	Aladdin	60
2	1961	Tammy Tell Me True	Neil Bateman	57
3	1962	Sammy, the Way-Out Seal	Petey Loomis	63
4	1963	A Child Is Waiting	Child	68
5	1963	A Ticklish Affair	Alex Martin	57
6	1963	Palm Springs Weekend	Boom Boom Yates	50
7	1964	For the Love of Willadean	Freddy Gray	60
8	1965	Lost in Space - No Place to Hide	Will Robinson	0
9	1965	Dear Brigitte	Erasmus 'Ras' Leaf	64
10	1968	Wild in the Streets	Boy (uncredited)	60
11	1969	Rascal	Sterling North	58
12	1971	Bless the Beasts & Children	Lawrence Teft	68
13	1973	Sunshine	Weaver	69
14	1973	Papillon	Lariot	78
15	1974	The Rockford Files	Nick Butler	0
16	1977	Sunshine Christmas	Weaver	0
17	1980	Fish Heads		0
18	1983	Twilight Zone: The Movie	Tim	65
19	1984	Hard to Hold	The James Roberts Band - Keyboard	44
20	1987	Zabagabee	Art Barnes	0
21	1990	Captain America	Young General Fleming	45
22	1992	Double Trouble	Bob	47
23	1995	Three Wishes	Neighbor	62
24	1996	Underground Adventure	Sam (voice)	0
25	1996	The Monkey Prince	Sam (voice)	0
26	1998	Lost In Space Forever	Self (also archive footage)	68
27	1999	Attack of the 50 Foot Monster Mania	Narrator	70
28	2000	Boom! Hollywood's Greatest Disaster Movies	Self - Host	0
29	2000	Behind The Dementia	himself	0
30	2002	Larry 'Wild Man' Fischer	Self	0
31	2004	Comic Book: The Movie	Bill Mumy	58
32	2005	Ringers: Lord of the Fans	Self	63
33	2005	Derailroaded	Self	76
34	2006	Look, Up in the Sky! The Amazing Story of Superman	Self	75
35	2006	A.I. Assault	Major Keith	52
36	2006	Holly Hobbie and Friends: Christmas Wishes	Bud Morris / Judge #1 (voice)	0
37	2007	Holly Hobbie and Friends: Surprise Party	Bud Morris (voice)	0
38	2009	The Face is Familiar	Narrator	20
39	2018	What We Left Behind: Looking Back at Star Trek: Deep Space Nine	Self	71
40	2023	Babylon 5: The Road Home	Lennier (voice)	68
41	2024	Space Command Redemption	Greg Mazzey	60

Television

No.	Year	Title	Role	Vote Average
1	1950	The Jack Benny Program	Little Boy Who Weighs Himself	78
2	1953	General Electric Theater	Buzz	63
3	1953	Letter to Loretta	Rennie	65
4	1953	Letter to Loretta	Jimmy Harrison	65
5	1954	The Wonderful World of Disney	Petey Loomis	78
6	1954	The Wonderful World of Disney	Freddy Gray	78
7	1955	Alfred Hitchcock Presents	Jackie Chester	77
8	1955	Alfred Hitchcock Presents	Mickey Hollins	77
9	1957	Have Gun, Will Travel	Little Boy at Carlton Hotel	74
10	1957	Wagon Train	Toddy	63
11	1957	Perry Mason	Miles	77
12	1959	The Twilight Zone	Billy Bayles	84
13	1959	The Twilight Zone	Anthony Fremont	84
14	1959	The Twilight Zone	Young Pip	84
15	1960	National Velvet		75
16	1961	Kraft Mystery Theatre		60
17	1961	Dr. Kildare	Jeffey	55
18	1961	Ben Casey		56
19	1962	The Virginian	Willy	65
20	1962	The Alfred Hitchcock Hour	Tony Mitchell	78
21	1962	Going My Way		57
22	1962	The Eleventh Hour		60
23	1963	Vacation Playhouse	Chris Williams	70
24	1963	The Fugitive	David Taft	72
25	1963	The Greatest Show on Earth	Jeff	50
26	1964	Bewitched	Michael	79
27	1964	The Munsters		79
28	1965	Lost in Space	Will Robinson	71
29	1965	I Dream of Jeannie	Custer	78
30	1968	Lancer		47
31	1974	The Rockford Files	Trask	75
32	1975	Sunshine	Weaver	55
33	1986	Matlock		71
34	1988	Superboy		64
35	1990	The Flash	Roger Braintree	74
36	1991	The Ren & Stimpy Show		76
37	1992	Batman: The Animated Series	The Fox (voice)	85
38	1993	Star Trek: Deep Space Nine	Kellin	79
39	1993	Diagnosis: Murder	Parker Craddick	71
40	1994	Babylon 5	Lennier	80
41	1994	Space Ghost Coast to Coast		78
42	1994	The Steven Banks Show	Billy Mumy	70
43	1996	Space Cases		70
44	1997	The Weird Al Show		64
45	2000	Buzz Lightyear of Star Command	Eon (voice)	65
46	2001	TVography		0
47	2001	Crossing Jordan	Paper Shredder Operator	72
48	2002	What's New, Scooby-Doo?	Harry Noze (voice)	79
49	2002	The Twilight Zone	Anthony Fremont	72
50	2006	Holly Hobbie & Friends	Bud Morris (voice)	100
51	2010	Ben 10: Ultimate Alien	Agent Bryson (voice)	82
52	2012	Bravest Warriors	Ralph Waldo Pickle Chips	77
53	2016	The Loud House	Timothy Mccole	78
54	2018	Lost in Space	Real Dr. Smith	75
55	2018	Lost in Space	Dr. Zachary Smith	75
56	2021	Toon In with Me	Self	77
57	2024	The D-Con Chamber	Self	0