- O'Connor-Fyffe, Adv. (1)
- Office of Jugoslav Member Inter-Allied Information Center (1)
- Office of War Information. Graphics Division (1)
- Officine dell 'Istituto Italiano d 'Arti Grafiche ; Pubblicita d 'Arte Crespi e Cortina (1)
- Offsetdruck Edmund Gaillard (1)
- Offsetdruck Edmund Gaillard G.m.b.H. (2)
- Offsetdruck Langebartels u. Jurgens (1)
- Offsetdruck Langebartels und Jurgens (1)
- Offsettiefdruck J.C. Konig & Ebhardt (1)
- Oldsmobile Division, General Motors Corp. (4)
- Oldsmobile Division, General Motors Corporation, 1942 (1)
- Ostdiek Co. (1)
- Otis Litho. Co. (1)
- Otis Lithograph Co. (6)
- Ottawa : Issued by the Director of Public Information for the Department of Munitions and Supply. (1)
- Ottawa : Wartime Information Board (2)
- Otto Dinse (1)
- Otto Hinz (1)
- Otto Holzhauser (1)
- Otto Wefers (1)
