Check out what might be the first time that charleston dance is depicted in a commercially released sound film. Entitled "A Night in Dixie", dated 1926, the film was part of a series of "Phonofilm" shorts produced in 1925 and 1926 by Lee De Forest.
From the YouTube description:
That blackface makeup is just horrible, of course. Which is a shame, since Hudgins' dancing is pretty fantastic. Anyway, check out the whole thing here.
We have not found any references to earlier commercial films that depict the charleston. If you know of any, share them in the comments.
Hattip: swingindenver on Reddit.