The Mouthpiece

Warren William

Vincent 'Vince' Day

Sidney Fox

Celia Farraday

Aline MacMahon

Miss Hickey, Day's Secretary

John Wray

Mr. Barton

Mae Madison

Elaine

Ralph Ince

J.B. Roscoe

Morgan Wallace

E.A. Smith

Guy Kibbee

Bartender

J. Carrol Naish

Tony Rocco

Walter Walker

District Attorney Forbes

Stanley Fields

Mr. Pondapolis

Murray Kinnell

Thompson, Day's Butler

Noel Francis

Miss DeVere

William Janney

John 'Johnny' Morris

Emerson Treacy

Robert Wilson (Uncredited)

Jack La Rue

Joe Garland (Uncredited)

Polly Walters

Gladys (Uncredited)

Berton Churchill

Rocco Trial Judge (Uncredited)

Davison Clark

Detective Arresting Garland (Uncredited)

Kenne Duncan

Office Worker (Uncredited)

Helena Phillips Evans

Crying Prospective Client (Uncredited)

Willie Fung

Chinese Waiter (Uncredited)

Paulette Goddard

Platinum Blonde at Party (Uncredited)

John Kelly

Cab Driver (Uncredited)

Hector Sarno

The Gardener-Murderer (Uncredited)

Eric Wilton

Maitre d' (Uncredited)

Charles Lane

Hotel Desk Clerk (Uncredited)

Selmer Jackson

Prison Clerk (Uncredited)

Pedro Regas

One of J.B.'s Henchmen (Uncredited)

Lew Harvey

One of J.B.'s Henchmen (Uncredited)