George O'Brien
— Gordon Harrington, Jr. aka John 'Whispering' Smith
Irene Ware
— Nan Roberts
Kenneth Thomson
— J. Wesley Hunt
Maude Allen
— Mrs. Roberts
Spencer Charters
— Cal Stone
Victor Potel
— Bill Prouty
Edward Keane
— Rebstock
Frank Sheridan
— Gordon Harrington, Sr.
William V. Mong
— Blake
Maurice Cass
— C. Luddington Colfax
Allan Cavan
— Harrington Office Worker (uncredited)
Bess Flowers
— Secretary (uncredited)
John Ince
— Conductor (uncredited)
Si Jenks
— Oiler (uncredited)
J.P. McGowan
— Caboose Passenger (uncredited)
Dick Rush
— Denver Police Chief (uncredited)