Encyclopedias, Almanacs, Transcripts, and Maps
- Oppenheim, Paul Leo
- Oppenheim, Philipp
- Oppenheim, Sally
- Oppenheimer, Carl
- Oppenheimer, Franz
- Oppenheimer, Fritz E.
- Oppenheimer, Hillel (Heinz) Reinhard
- Oppenheimer, Joseph
- Oppenheimer, Joseph ben Issachar Suesskind
- Oppenheimer, Karl
- Oppenheimer, Samuel
- Oppenheimer, Sir Ernest
- Oppenhejm, Ralph Gerson
- Opper, Frederick Burr
- Oppert, Gustav Salomon
- Oppert, Jules Julius
- Optatus of Milevis, St.
- Optimism
- Optimism (Theological Aspect)
- Option for the Poor