On screen
Cast
148 credited performers
Guy Williams
Dr. John Robinson
June Lockhart
Dr. Maureen Robinson
Mark Goddard
Major Don West
Marta Kristen
Judy Robinson
Angela Cartwright
Penny Robinson
Bill Mumy
Will Robinson
Jonathan Harris
Dr. Zachary Smith
Dick Tufeld
Robot B-9
Bob May
Robot B-9
Dawson Palmer
Cosmic Monster
Fritz Feld
Mr. Zumdish
Sheila Allen
Ruth Templeton
Ron Gans
Alien Leader
Dee Hartford
Verda
Leonard Stone
Farnum
Albert Salmi
Captain Alonzo P. Tucker
Michael Rennie
The Keeper
Vitina Marcus
Lorelei
Michael Fox
Cybernetic Leader / Supreme Brain (voice)
Don Matheson
IDAK Alpha 12
Joe E. Tata
Purple Robot (voice)
Don Forbes
TV Commentator
Theodore Lehmann
Disk (voice)
Gregory Morton
Canto of Quasti (voice)
Allan Melvin
Enforcer Claudio
Tiger Joe Marsh
Security Guard
Hoke Howell
Sgt. Rogers
Sue England
Female Robot (voice)
William Bramley
Mr. Nobody
Keith Taylor
Theodore the bully
Robert Foulk
Cragmire
Marcel Hillaire
Phanzig
Fred Krone
Monster
Ted Cassidy
Slave
Melinda O. Fee
Fenestra
Wally Cox
Tiabo
Dennis Patrick
Keema
Strother Martin
Nerim
Mike Kellin
Myko
Henry Jones
Jeremiah Smith
Gerald Mohr
Morbus
Mickey Manners
Dee
Torin Thatcher
The Space Trader
Michael J. Pollard
The Boy
Michael Ansara
The Ruler
Hans Conried
Sagramonte
Wilbur Evans
Lighted Head Leader
Lamar Lundy
The Giant Cyclops
John Carradine
Arcon
Sean McClory
Hamish
Al Lewis
Zalto
Francine York
Niolani
Werner Klemperer
Bolix
Warren Oates
Jimmy Hapgood
Robert Easton
Newsman Lacy
Frank Delfino
Character not listed
Ronald Long
Admiral Zahrk
Kevin Hagen
Alien
Lew Gallo
Cmdr. Fletcher
Arthur Batanides
Rongah
Kym Karath
Princess
Lyle Waggoner
Mechanical Man
Daniel J. Travanti
Space Hippie
Stanley Adams
Tybo
Vincent Beck
Megazor
Abraham Sofaer
Sobram
Mercedes McCambridge
Sybilla
Michael Conrad
Creech
Lou Wagner
J-5
John Crawford
Dr. Chronos
Eddie Quillan
Bartender
Malachi Throne
Thief
Walter Burke
O. M.
Peter Brocco
Alien Leader
Janos Prohaska
Bird Monster
James Westerfield
Dr. Marvello
Kurt Russell
Quano
Larry Ward
Ohan
Reta Shaw
Aunt Clara Simms
John Abbott
Sesmar
Sherry Jackson
Effra
Arte Johnson
Fedor
Tol Avery
Warden
Liam Sullivan
Nexus
Royal Dano
Major Domo
Woodrow Parfrey
Col. Silas Fogey
Edy Williams
Non
Chuck Roberson
Alien Fighter
Lane Bradford
Barfly
Helen Kleeb
Phone Operator Rachel
Brett Parker
Security Guard
Ford Rainey
The President
Hal Torey
General
Fred Crane
Alpha Control Technician
Robert 'Big Buck' Maffei
The Giant Cyclops
Françoise Ruggieri
Moela
Charles Dierkop
Horned Mutant
Walter Sande
Sheriff George Baxendale
Donald Losby
Davey Sims
Harry Harvey
Grover
Anne Dore
First Selectman
Michael Greene
Nubu
Harry Monty
Geoo
Maxine Gates
Fat Princess
Ken Mayer
Pleiades Pete
Bill Troy
Alien
Harry Raybould
Urso
June Foray
Gundemar (voice)
Jeff County
Gundemar
Larry Dean
Wooden Soldier
Bern Hoffman
Thor
Jim Boles
Smeek
Craig Duncan
Deek
Alan Hewitt
Lemnoc
Jim Mills
Saticon
Duke Fishman
Convict
Ben Frommer
Convict
Lars Hensen
Convict
Gil Perkins
Convixt
Mike Morelli
Convict
Pitt Herbert
Grover
Claire Wilcox
Stacy
Norman Leavitt
Charlie
Robert Pine
Craig
Grant Sullivan
Alien
Carol Williams
Alien
Tommy Farrell
Cyborg
Bart La Rue
Alien Machine (voice)
Kenya Coburn
Zaybo
Don Eitner
Sgt. Smith
Linda Gaye Scott
Aien Girl
Ralph Lee
Mechanical Man
Gary Tigerman
Oggo
Ronald Weber
Mort
Tom Allen
Inspector (uncredited)
Carroll Roebke
Tat
Eric Matthews
QZW
Richard Krisher
MXR
Corinna Tsopei
Princess Reyka
Alberto Monte
Chavo
Jim Gosa
Gilt Proto
Byron Morrow
General Squires
Gil Rogers
Bartholomew
Charles Horvath
Guard
Miriam Schiller
Miss Teutonium
James Millhollin
Willoughby
Ollie O'Toole
Robotoid (voice) (uncredited)
Hal Jon Norman
Dog-faced Alien (uncredited)