Trivia

John Wayne and Robert Ryan managed to put aside their vast political differences while making this film, although Ryan was appalled by Wayne's support for blacklisting, extending the Korean War by launching nuclear strikes on Chinese cities, and using military force to drive the Soviets out of eastern Europe. However they later did not get along at all while filming The Longest Day (1962).

Marines got the nickname of "Leathernecks" from the fact that early uniforms had a collar made of leather which was intended to protect the throat from knife wounds.

This movie is often considered merely another assignment of Nicholas Ray's at RKO for Howard Hughes to prove his political and professional alliance during the Red Scare. A blatant pro-war movie that Hughes cared about and Ray did not, Ray disagreed with the film's politics and was said to get Robert Ryan to intentionally overact. Ryan and Ray, who were leftist liberals, constantly fought against John Wayne and Jay C. Flippen, who were conservatives and supported the Blacklist.

Lynn Stalmaster (uncredited), who played Castle (the second pilot shot down, whose belongings are inspected by Kirby), acted in only 5 movies. He made his name as a casting director, having been in charge of casting for an amazing 389 films and television shows over a 67-year career, including the 1978 blockbuster, Superman. His most recent casting job was in 2017 at the age of 90. His first casting job was in 1950, the same year that Flying Leathernecks was in production.

John Wayne's character in this movie, Major Daniel Xavier Kirby, was based on Captain John Lucian Smith, USMC Ace who was Commanding Officer in the Marine Fighting Squadron 223 at Guadalcanal in 1942 during World War II. Smith was a Medal of Honor recipient in 1943 and a leader of the "Cactus" Air Force. Smith, a wildcat fighter pilot, shot down nineteen Japanese airplanes over Guadalcanal in 1942. Smith's achievements and commendations were well known to the public prior to this film being made. Smith was eventually promoted to the rank of Lieutenant Colonel and likewise, Wayne's Kirby character is also promoted to the same rank in this movie. There is also a physical likeness and resemblance between Wayne and Smith.