In which Bette Davis starring film was Humphrey Bogart cast in a supporting role as an Irish stable trainer?
The Bette Davis film where Humphrey Bogart had a supporting role as an Irish stable trainer is
"The Bride Came C.O.D." (1941).
He played the role of "Barney 'The Baron' Quill", a lovable but rough-around-the-edges trainer who helps Davis' character, a "mail-order bride", get acclimated to life in the United States.