The role of Old Lodge Skins was initially offered to Marlon Brando, who turned it down. Other sources claim Arthur Penn's first choice for the role was Sir Laurence Olivier. When that didn't work out, Richard Boone was slated for the role. When Boone backed out at the last minute, Chief Dan George was given the part and earned an Oscar nomination.
Little Big Man was the name of an actual historical figure. He was a Native American, an Oglala Lakota, who was a fearless and respected warrior who fought under, and was rivals with, Crazy Horse. He also fought at the Battle of Little Big Horn, a battle which is depicted in this film.
Chief Dan George became the first Native American to receive an Academy Award nomination for acting.
As acknowledged in the film, the self chosen names of many American native tribes simply translate as "the human beings", leading to inevitable difficulties in translating and interpreting certain sayings in their languages.
In order to get the raspy voice of 121-year-old Jack, Dustin Hoffman sat in his dressing room and screamed at the top of his lungs for an hour.