Jack Lemmon as Professor Fate

Tony Curtis as The Great Leslie

Natalie Wood as Maggie Dubois

Peter Falk as Max

Keenan Wynn as Hezekiah

Arthur O'Connell as Henry Goodbody

Vivian Vance as Hester Goodbody

Dorothy Provine as Lily Olay

Larry Storch as Texas Jack

Ross Martin as Rolfe Von Stuppe

George Macready as General Kuhster

Marvin Kaplan as Frisbee

Hal Smith as Mayor of Boracho

Denver Pyle as Sheriff

William Bryant as Baron's Guard

Ken Wales as Baron's Guard

Hal Needham as Saloon Brawler (uncredited)

Raoul Retzer as Mayor-Domo (uncredited)

Leslie Sketchley as Executive Board Member (uncredited)

Kenner G. Kemp as Townsman (uncredited)

Bert Stevens as Townsman (uncredited)

Arthur Tovey as Reporter (uncredited)

Chuck Hayward as Soldier (uncredited)

George Boyce as Executive Board Member (uncredited)

Jerry Schumacher as Auto Worker (uncredited)

Charles Fredericks as Master of Ceremonies (uncredited)

Max Wagner as Barfly (uncredited)

Paul Bryar as Policeman (uncredited)

Jack Gordon as Observer at Start (uncredited)

Sol Gorss as Saloon Brawler (uncredited)

Harry Harvey as Executive Board Member (uncredited)

Bob Herron as Palace Guard (uncredited)

Chuck Hicks as Saloon Brawler (uncredited)

Christopher Riordan as Cowboy / Dancer (uncredited)

Charles Seel as Freight Agent (uncredited)

Paul Smith as First Employee (uncredited)

Tom Steele as Saloon Brawler (uncredited)

Dale Van Sickel as Driver in Green Car (uncredited)

Sam Harris as Man in Hallway at Sentinel (uncredited)