Dick Van Dyke as Claude R. Fitzwilliam

Barbara Feldon as Juliet Nowell

John McGiver as Albert

Edith Evans as Miss Victoria Woodworth

Harry Townes as Mr. Nowell

John Fiedler as Mr. Morton Dunne

Anne Seymour as Grimsby

Norman Fell as Oberblatz

Cecil Kellaway as Buckmaster

Stephen Strimpell as Byron Casey

Helen Kleeb as Mrs. Mortimer

Paul Reed as Prettikin

Albert Carrier as Pierre

Nelson Olmsted as Simmons

Dennis Cooney as Assistant D.A. Elliot Adams

Noam Pitlik as Charles

Anthony Eustrel as Garland

Sam Waterston as Oliver

Karen Norris as Kitty

Patience Cleveland as Dolly

Lew Brown as Frank

Monroe Arnold as Goldfarb

Robert Williams as Ryan

Laurence Naismith as Mr. Cotty (uncredited)

Barbara Morrison as Mrs. Mudge (uncredited)

Kenner G. Kemp as Bar Patron (uncredited)

Fletcher Allen as Reporter (uncredited)

Merie Earle as Elderly Shoplifter (uncredited)

John Alban as Customer (uncredited)

Ruth Foster as Customer (uncredited)

Meg Wyllie as Saleswoman (uncredited)

Arthur Peterson as Liquor Store Clerk (uncredited)

John Daheim as Man Who Gets Slapped (uncredited)

Gary Dubin as Kid (uncredited)

Ethelreda Leopold as Customer (uncredited)

Arthur Tovey as Bar Patron (uncredited)

Dick Cherney as Bar Patron (uncredited)