Allied Forces:
* John Wayne as General Theodore "Ted" "Spike" Buckley
* Henry Fonda as General Norman Cota
* Robert Mitchum as Colonel Benjamin Vandervoort
* Richard Burton as Lieutenant Colonel John "Jock" Stirling
* Sean Connery as Sergeant Ryan
* Red Buttons as Private "Snafu" Aloysius "Al" Foley
* Peter Lawford as Lieutenant Colonel John "Jerry" C. S. Ward
* Rod Steiger as Sergeant Lipp
* Jeffrey Hunter as Captain Miller
* Paul Anka as Private Joe "The Yank" Ryan
* Robert Wagner as Lieutenant "Pinky" Pinkerton
* Eddie Albert as Lieutenant Colonel "Dutch" Van Bissbroeck
* Sal Mineo as Private Carwood
* Mel Ferrer as Colonel Charles de Gaulle
* Curd Jürgens as Colonel von Stauffenberg
* Stuart Whitman as Lieutenant "Doc" Holliday
Axis Forces:
* Robert Ryan as General Rommel
* Paul Hartmann as Field Marshal Erwin Rommel
* Curt Bois as Major Von der Heydte
* Siegfried Rauch as Captain Von Lossberg
* Hans Christian Blach as Lieutenant Colonel Schumacher
This is just a partial list, as the film had a huge cast of over 150 actors. "The Longest Day" was a monumental production, and the impressive cast reflects the historical significance of the D-Day invasion.