Knockout Reilly is a lost[1][2] 1927 American silent drama film directed by Malcolm St. Clair and written by Pierre Collings, John W. Conway, and Kenneth Raisbeck based upon a story by Albert Payson Terhune.

The film stars Richard Dix, Mary Brian, Jack Renault, Harry Gribbon, Osgood Perkins, and Lucia Backus Seger.

[3][4][5] When a successful prizefighter known as "Killer" Agerra causes trouble in a nightclub, a New Jersey mill worker, Dundee Reilly, knocks him out.

While incarcerated, he keeps up his training.When he gets out, Agerra's opponent in an upcoming fight drops out, so Pat Malone arranges for "Knockout" Reilly to be his replacement in the ring.

[8] Among these are Graham MacNamee, who covered the 1927 broadcast of Dempsey-Tunney heavyweight match, announcer Joe Humphreys appears as himself covering the staged fight between Dix and Renault, Patsy Haley as referee, trainer Jimmy DeForrest (who trained Jack Dempsey), boxer Kid McPartland, as timekeeper, former featherweight Larry McGrath, bantam-weight champ Ted "Kid" Lewis, light heavyweights Billy Vidabeck and Jack Perry, and prizefighter Scotty Devlin, who plays Dix’s chauffeur in the film.