Julie Christie

Susan Harris

Fritz Weaver

Alex Harris

Gerrit Graham

Walter Gabler

Berry Kroeger

Petrosian

Lisa Lu

Soong Yen

Larry J. Blake

Cameron

John O'Leary

Royce

Alfred Dennis

Mokri

Davis Roberts

Warner

Patricia Wilson

Mrs. Talbert

Michelle Stacy

Marlene

Felix Silla

Baby

Barbara O. Jones

Technician

Peter Elbling

Scientist

Robert Vaughn

Proteus IV (voice) (uncredited)