- Joey Cramer
- David Freeman
- Paul Reubens
- Max
- Cliff De Young
- Bill Freeman
- Veronica Cartwright
- Helen Freeman
- Sarah Jessica Parker
- Carolyn McAdams
- Albie Whitaker
- Jeff (8 years)
- Matt Adler
- Jeff (16 years)
- Howard Hesseman
- Dr. Louis Faraday
- Robert Small
- Troy
- Jonathan Sanger
- Dr. Carr
- Iris Acker
- Mrs. Howard
- Richard Liberty
- Mr. Howard
- Raymond Forchion
- Detective Banks
- Cynthia Caquelin
- Woman Officer
- Ted Bartsch
- Night Guard Brayton
- Gizelle Elliott
- Technician #1
- Brigid Cleary
- Technician #2
- Michael Strano
- Technician #3
- Parris Buckner
- Scientist #1
- Robyn Peterson
- Scientist #2
- Tony Tracy
- Observation Guard
- Philip Hoelcher
- NASA Officer
- Julio Oscar Mechoso
- Hangar Guard #1
- Butch Raymond
- Hangar Guard #2
- Bob Strickland
- Control Room Guard #1
- Michael Brockman
- Control Room Guard #2
- Louis Cutolo
- Radar Technician #1
- Debbie Casperson
- Radar Technician #2
- Chase Randolph
- Lieutenant King
- John Archie
- Agent #1
- Tony Calvino
- Agent #2
- Rusty Pouch
- Gas Station Attendant
- Robert Goodman
- Tourist Man
- Ryan Murray
- Tourist Child
- Keri Rogers
- Jennifer Bradley
- Peter Lindquist
- Newscaster #1
- Jill Beach
- Newscaster #2
- Kenneth Ian Davis
- Kid in Mustang
- Bruce Laks
- Bixby
- Arnie Ross
- NASA Technician #1
- Fritz Bronner
- NASA Technician #2
- Tony Urbano
- Puppeteer
- Tim Blaney
- Puppeteer
- Corey Burton
- R.A.L.F.
