The Devil Within is a 1921 American silent adventure film directed by Bernard J. Durning and starring Dustin Farnum, Virginia Valli and Nigel De Brulier.

As an old man, he has reformed, but his grandson, Hal, enters into the same wild lifestyle.

[2] Jessie Robb of The Moving Picture World gave the film a negative review, criticizing the "poor" story and "uneven action," as well as the feeling that the film's runtime was padded with a large amount of unnecessary close-ups.

Robb concluded "It does not seem equal to Dustin Farnum's previous release.

Wid's Daily wrote, "Farnum gets terrible story for his second," and Motion Picture News felt it was "Not up to 'Primal Law'".