Peter Sellers as Chance

Shirley MacLaine as Eve Rand

Melvyn Douglas as Benjamin Rand

Jack Warden as President 'Bobby'

Richard Dysart as Dr. Robert Allenby

Richard Basehart as Vladimir Skrapinov

Ruth Attaway as Louise

David Clennon as Thomas Franklin

Fran Brill as Sally Hayes

Denise DuBarry as Johanna Franklin

Alice Hirson as First Lady

Jerome Hellman as Gary Burns

John Harkins as Sidney Courtney

James Noble as Kaufman

Mitch Kreindel as Dennis Watson

Oteil Burbridge as Lolo

Richard Venture as Wilson

Sam Weisman as Colson

Elya Baskin as Karpatov

Hal Ashby as Man at File Cabinet at the Washington Post (uncredited)

Kenneth Patterson as Perkins

Stanley Grover as Baldwin