Peter Lorre
Dr. Einstein
Edward Everett Horton
Mr. Witherspoon
Cary Grant
Mortimer Brewster
Josephine Hull
Aunt Abby Brewster
Jean Adair
Aunt Martha Brewster
Raymond Massey
Jonathan Brewster
Priscilla Lane
Elaine Harper Brewster
John Alexander
'Teddy Roosevelt' Brewster
Jack Carson
Officer Patrick O'Hara
John Ridgely
Officer Saunders
Edward McNamara
Sergeant Brophy
Hank Mann
Photographer at Marriage License Office (uncredited)
Leo White
Man in Phone Booth (uncredited)
Charles Lane
Reporter at Marriage License Office
Grant Mitchell
Reverend Harper
Chester Clute
Dr. Gilchrist
James Gleason
Lt. Rooney
Spencer Charters
Marriage License Clerk
Raymond Walburn
Drummer at baseball game (uncredited)
Edward McWade
Gibbs
Garry Owen
Taxi Cab Driver
Spec O'Donnell
Young Man in Line (uncredited)
Lee Phelps
Umpire (uncredited)
Vaughan Glaser
Judge Cullman