The Longest Day is a 1962 American epic war film based on Cornelius Ryan's 1959 non-fiction book of the same name about the D-Day landings at Normandy on June 6, 1944. The film was produced by Darryl F. Zanuck for 20th Century Fox, and is directed by Ken Annakin, Andrew Marton, and Bernhard Wicki. The screenplay was written by Ryan, with additional material written by Romain Gary, James Jones, David Pursall and Jack Seddon.

Darryl Francis Zanuck was an American film producer and studio executive; he earlier contributed stories for films starting in the silent era. He played a major part in the Hollywood studio system as one of its longest survivors. He produced three films that won the Academy Award for Best Picture during his tenure at 20th Century Fox.