Cesar Romero

Philip 'Phil' O'Dell

Bernadette O'Farrell

Heather McMara

Lois Maxwell

Margaret 'Peggy' Maybrick

Geoffrey Keen

Christopher Hampden

Campbell Singer

Inspector Rigby

Alastair Hunter

Det. Sgt. Reilly

Mary Mackenzie

Marilyn Durant

Lloyd Lamble

Martin Sorrowby

Frank Birch

Boswell - Airport Manager

Wensley Pithey

Sid - Bartender

Reed De Rouen

Connors

Peter Swanwick

Smithers

Richard Johnson

Danny McMara - Hit-and-Run Victim

Bill Fraser

Sales Manager

Lisa Lee

Donna Devore

Lionel Harris

Allan Mellon

Betty Cooper

Dr. Campbell - Asylum Superintendent

Clare James

Miss Andrews - Asylum Receptionist

Katie Johnson

Mad Mary - Old Inmate at Murder Scene

Jacques Cey

Head Waiter

Jean Bayless

Delmont Switchboard Operator (as Jean Bayliss)

Stuart Nichol

Steve

Marguerite Brennan

Desk Clerk at Heather's Apartment

Robert Adair

John - Film Director

Terry Carney

Minor Role (uncredited)

Robert Dorning

Airline Reservations Clerk (uncredited)

Josephine Douglas

Nurse at Glenhaven Sanatorium (uncredited)

Christina Forrest

Minor Role (uncredited)

Jack Howarth

Minor Role (uncredited)

Robert Moore

Minor Role (uncredited)

Stuart Saunders

Police Sergeant (uncredited)

Dorinda Stevens

Girl at Film Studio (uncredited)

Hazel Sutton

Minor Role (uncredited)

Larry Taylor

Hospital Attendant (uncredited)

James Ure

Airline Reservations Clerk (uncredited)