Encyclopedias, Almanacs, Transcripts, and Maps
- Oecolampadius, Johannes
- Oenomaus of Gadara°
- Oertel, John James Maximilian
- Oesterley, William Oscar Emil°
- Oesterreicher, John M.
- Oesterreicher, Tobias von
- Oesterreichische Nationalbibliothek
- Oesterreichisches Central Organ Fuer Glaubensfreiheit, Cultur, Geschichte und Literatur der Juden
- Oettingen
- Ofakim
- Ofek, Avraham
- Ofek, Uriel
- Ofer, Avraham
- Offenbach
- Offenbach, Isaac
- Offenbach, Jacques
- Offenburg
- Office for Film and Broadcasting
- Office of Special Investigations
- Office of the Dead