- Pat O'Brien
- Francis William 'Frank' / 'Cav' Cavanaugh
- Ruth Warrick
- Florence Ayres Cavanaugh
- Robert Ryan
- Father Timothy 'Tim' Donovan
- Leon Ames
- Robert 'Bob' Stewart
- Russell Wade
- P:vt. Manning
- Bruce Edwards
- Lt. Jones
- Richard Martin
- David 'Davie' Cavanaugh
- Kirk Alyn
- John Cavanaugh
- Robert Andersen
- Minor Role
- Steve Barclay
- Football Player
- Brandon Beach
- George - Dartmouth Alumnus
- Brooks Benedict
- Dartmouth Alumnus
- Dean Benton
- William Cavanaugh
- Robert Benton
- Football Player
- Robert Bice
- High School Coach
- Louis Borel
- French Officer
- Bonnie Braunger
- Baby
- Virginia Brissac
- Mrs. Ayres
- Walter Brooke
- Lt. Stone
- Charles D. Brown
- Fordham Official
- Wheaton Chambers
- Army Doctor
- Russ Clark
- Football Umpire
- Gordon B. Clarke
- Student
- James Courtney
- Boston College Player
- Joseph Crehan
- Judge
- Mary Currier
- Troop Ship Nurse
- Richard Davies
- Chuck
- Joel Davis
- Davie Cavanaugh - as a Boy
- Dickie Dillon
- Boy
- John Dilson
- Doctor
- Roland Dupree
- Boy
- Elena Durán
- Dancer
- Walter Fenner
- Army Doctor in France
- Craig Flannagan
- Coach
- James Flavin
- Football Umpire
- William Forrest
- Fordham Official
- John Frederick
- Yale Captain
- Bud Geary
- Sergeant
- Barbara Hale
- Sarah Cavanaugh
- Mary Halsey
- Student
- Chuck Hamilton
- Fordham Player / Officer at Swearing-In (uncredited)
- Florence Hansen
- Bob's Girlfriend
- Josh Hardin
- Man
- Eddie Hart
- Bailiff
- Lew Harvey
- Lieutenant
- Myron Healey
- Paul Cavanaugh
- Louis Jean Heydt
- Recruiting Sergeant
- Teddy Infuhr
- Davie - as Boy
- Jimmy Jordan
- Philip Cavanaugh
- Sid Jordan
- Driver
- Milton Kibbee
- Mr. Watkins
- Victor Kilian Jr.
- Francis Cavanaugh Jr.
- Joe King
- Defense Attorney
- Fred Kohler Jr.
- Boston College Captain
- Mike Lally
- Minor Role
- Harold Landon
- Boston College Player
- Margaret Landry
- Sarah Cavanaugh - as a Girl
- Bobby Larson
- Boy
- Paul Le Pere
- Court Clerk
- Larry Lund
- Football Player
- Bonnie Lynn
- Young Girl
- James Magill
- Student
- Greg McClure
- Boston College Player
- Sam McDaniel
- Pete - Train Porter
- Paul McVey
- Athletic Coach
- John Miljan
- Oregon State Coach
- Michael Miller
- Boy
- Bert Moorhouse
- Dartmouth Alumnus
- Georgie Nokes
- Boy
- William H. O'Brien
- Waiter
- Joe O'Connor
- Second Defense Attorney
- Pat O'Malley
- Charlie
- Lee Phelps
- Soldier
- Cyril Ring
- Ross
- Mike Road
- Minor Role
- Walt Robbins
- Driver
- Henry Roquemore
- Young Frank's Neighbor
- Ramon Ros
- Dancer
- William Roy
- Bob - as a Boy
- Frank Shannon
- Pa Cavanaugh
- Mel Shubert
- Boston College Player
- Sada Simmons
- Nurse
- Dok Stanford
- Soldier
- Bob Thom
- Soldier
- Harry Tyler
- Friend
- George Tyne
- Boston College Player
- Dorothy Vaughan
- Ma Cavanaugh
- Pierre Watkin
- Col. White
- John B. Williams
- Pullman Porter
- Marie Windsor
- Young Woman at Dock
- Robert Winkler
- Frank Cavanaugh - as a Boy
- Steve Winston
- Student
- Rudy Wissler
- Boy
- Eddie Woods
- Friend
