Throughout the movie the name of Custer's subordinate is incorrectly being pronounced as "Benton" when his name actually "Benteen"
There was a post indicating that the battle took place in 1875, when in fact the battle occurred on June 25, 1876.
Location scenes filmed in Tucson, Arizona.
The Great Sioux Massacre (1965)'s premiere in Minot, ND was near the site of the battle portrayed in the film.
Working titles of The Great Sioux Massacre (1965) were The Custer Massacre and Massacre at the Rosebud.