Robert Vaughn

as Napoleon Solo

David McCallum

as Illya Kuryakin

Jack Palance

as Louis Strago

Janet Leigh

as Miss Diketon

Eduardo Ciannelli

as Arturo 'Fingers' Stilletto

Allen Jenkins

as Enzo 'Pretty' Stilletto

Jack La Rue

as Federico 'Feet' Stilletto

Leo G. Carroll

as Alexander Waverly

Joan Blondell

as Mrs. 'Fingers' Stilletto

Ludwig Donath

as Dr. Heinrich von Kronen

Will Kuluva

as Mr. Thaler, Thrush Boss

Letícia Román

as Pia Monteri

Penny Santon

as Grandma Monteri

Frank Puglia

as Padre

Vincent Beck

as Benjamin Luger

Maxie Rosenbloom

as 'Crunch' Battaglia

Vince Barnett

as 'Scissors'

Elisha Cook Jr.

as Arnold

James Almanzar

as Thrush Captain

Clarke Gordon

as Thrush Officer

Jesslyn Fax

as Mrs. Feinberg

Jimmy Bates

as Boy

David Renard

as Donkey Man

Sharyn Hillyer

as Miss Gorgeous

Anne Caprile

as Miss Diketon (french voice) (uncredited)

Leoda Richards