* CaliforniaDoubling: Yugoslavia doubled for Nazi-occupied France.
* ContractualObligationProject: Creator/ClintEastwood signed to do the film mainly because his friend and favorite director, Don Siegel, was set to direct it. However, Siegel ran into post-production problems while finishing up ''Film/TwoMulesForSisterSara'' and had to withdraw from the project. Brian G. Hutton was then signed to direct. Eastwood, who previously worked with Hutton on ''Film/WhereEaglesDare'' and had already signed a contract to do the film, couldn't pull out.
* DeletedRole: Production designer John Barry (not the [[Music/JohnBarry composer]]) as a British airmen hiding in the town who witnesses the final battle.
* DeletedScenes: The studio cut 20 minutes from the film. Deleted material includes:
** Oddball and his crew pack up to go across the lines to meet up with Kelly and others while local village girls are running around half naked.
** The platoon encounters a group of German soldiers and naked girls swimming in a pool.
** While they wait for Oddball in the barn at night, Kelly and Big Joe talk about their disillusionment with the war and why Kelly was made as a scapegoat for the attack that resulted in his demotion. Another scene was deleted from this part where the platoon decides they do not want to continue with the mission, and Gutowski threatens Kelly at gunpoint, but Big Joe and Crapgame side with Kelly.
** General Colt is in bed with some women when he gets a call that Kelly and others have broken through the enemy lines.
** During the attack on the town, production designer Jon Barry had a cameo as a British airman hiding from the Germans.
** One promotional still shows Kelly finding a wounded German soldier among the ruined houses during the final town attack.
** Kelly, Oddball and Big Joe discuss tactics while standing on an abandoned Tiger tank before the scene where they negotiate with the German tank commander.
** When Kelly and platoon drive off at the end, a bunch of soldiers yell at them that they are headed in the wrong direction.
* ExecutiveMeddling: According to Creator/ClintEastwood, Creator/{{MGM}}, against both his wishes and those of director Brian G. Hutton, re-edited the film to remove some character-driven scenes and a more obvious anti-war message. This was also responsible for the addition of "Burning Bridges" as the title song, rather than the original theme composed by Music/LaloSchifrin.
* ReferencedBy:
** This film is an obvious favorite of the makers of ''Anime/GirlsUndPanzer'':
*** One character calls herself "Sargent Oddball" as a hasty alias
*** Another team of girls watches the movie for inspiration the night before the national finals.
*** Said team then invokes "Operation ''Kelly's Heroes''" in that final battle.
** ''VideoGame/AceCombat6FiresOfLiberation'' features a subplot about a tank crew sneaking behind enemy lines to rob a bank vault. They go into a tunnel system and break through a wall to find [[spoiler: some street kids who had been trapped along with a statue of great symbolic importance.]]
* WhatCouldHaveBeen: The film was going to have a female role, but prior to filming, it was cut from the script. Creator/IngridPitt, who was cast in the role, (and had been in ''Film/WhereEaglesDare'' with Creator/ClintEastwood the prior year) revealed that she was virtually climbing on board the plane bound for Yugoslavia when word came through that her part had been cut.
* WorkingTitle: ''The Warriors'' and ''Kelly's Warriors''.
----