William Bendix
— George Herman 'Babe' Ruth
Claire Trevor
— Claire Hodgson Ruth
Charles Bickford
— Brother Matthias
Sam Levene
— Phil Conrad
William Frawley
— Jack Dunn
Gertrude Niesen
— Nightclub Singer
Fred Lightner
— Miller Huggins
Stanley Clements
— Western Union Boy
Robert Ellis
— Babe Ruth as a Boy (as Bobby Ellis)
Lloyd Gough
— Gambler Dalton
Matt Briggs
— Colonel Jacob Ruppert
Paul Cavanagh
— Dr. Menzies
Warren Douglas
— Boston Braves' Rookie
Pat Flaherty
— Bill Carrigan, Red Sox Manager
Mark Koenig
— Mark Koenig
Richard Lane
— Boston Braves' coach
Ziggy Sears
— Umpire Ziggy Sears
Bucky Harris
— Bucky Harris - Baseball Player
Harry Wismer
— Harry Wismer - Sports Announcer
Mel Allen
— Mel Allen - New York Yankees Radio Announcer
H.V. Kaltenborn
— H. V. Kaltenborn - Radio News Commentator
Knox Manning
— Narrator
Al Bain
— Barfly (uncredited)
Oliver Crawford
— Reporter (uncredited)