Ocean Film Corporation
Octagon Films, Incorporated
Ogden Film Company
O.G. Film Company
Oklahoma Natural Mutoscene Company
Oliver Films
The Oliver Morosco Photoplay Company
Ollendorff Productions

Ontario Motion Picture Bureau
Ornak
Orplid Film
Oswald-Film
Outlook Photoplays
Out of the Inkwell Films, Incorporated
Owen Moore Film Corporation
Oz Film Manufacturing Company

See also:
Olcott, Sidney  >  Sidney Olcott Players, Incorporated, and Sid Films
101-Bison Company > New York Motion Picture Company