George Sanders as Robert Fleming

Lucille Ball as Sandra Carpenter

Charles Coburn as Harley Temple

Boris Karloff as Charles van Druten

Cedric Hardwicke as Julian Wilde

Joseph Calleia as Nicholas Moryani

Alan Mowbray as Lyle Maxwell

George Zucco as H.R. Barrett

Robert Coote as Detective Wilson

Alan Napier as Detective Gordon

Tanis Chandler as Lucy Barnard

Ann Codee as Matilda

Jimmy Aubrey as Nelson (uncredited)

Jack Chefe as Pierre (uncredited)

Charles Coleman as Sir Charles (uncredited)

Alex Frazer as Professor Harkness (uncredited)

Gerald Hamer as Harry Milton (uncredited)

Eddie Parks as Oswald Pickering (uncredited)

Dorothy Vaughan as Mrs. Miller (uncredited)

Stuart Hall as Charles (uncredited)

Herbert Evans as Fleming's Butler (uncredited)

Sam Harris as Old Man at Concert Asking for Whiskey (uncredited)

Isabel La Mal as Dowager Shushing Fleming at Concert (uncredited)

Marjorie Hoshelle as Robert's Rejected Girlfriend (uncredited)

Charles Ferguson as Man in Dance Hall (uncredited)

Ethan Laidlaw as Man in Dance Hall (uncredited)

Mike Lally as Mike (uncredited)

Ethelreda Leopold as Blonde Nightclub Singer (uncredited)

Annette Warren as Blonde Nightclub Singer (uncredited)

Mary Jane French as Nightclub Patron (uncredited)

Shep Houghton as Nightclub Patron (uncredited)

Sol Murgi as Nightclub Patron (uncredited)

Wilson Benge as Police Criminologist (uncredited)

Jack Deery as Police Officer (uncredited)

John Rice as Police Officer (uncredited)

Brooks Benedict as Concertgoer (uncredited)

Carl M. Leviness as Concertgoer (uncredited)

James Conaty as Concertgoer (uncredited)

Robert Haines as Concertgoer (uncredited)

Wilbur Mack as Concertgoer (uncredited)

Herschel Graham as Concertgoer (uncredited)

Rudy Germane as Concertgoer (uncredited)

Frank McLure as Concertgoer (uncredited)

Jeffrey Sayre as Concertgoer (uncredited)

Sayre Dearing as Concertgoer in Lobby (uncredited)

Harold Miller as Concertgoer in Lobby (uncredited)

Cyril Delevanti as Medical Examiner (uncredited)

Wyndham Standing as Assistant Medical Examiner (uncredited)

Eric Wilton as Ticket Booth Clerk (uncredited)

Florence Wix as Blue Eyes (uncredited)

Marion Gray as Concertgoer (uncredited)

Joe Gilbert as Concertgoer (uncredited)