Creator
- O'Boyle, Bob1
- O'Brien, Edwin1
- O'Daniel, Therman B. (Therman Benjamin), 1908-19861
- O'Donovan, William Rudolph, 1844-19201
- O'Shaughnessy, Arthur William Edgar, 1844-18811
- O'Shaugnessy, P.S.1
- O.C. Harn1
- Oberly, Aaron S., 1837-19189
- Obregón, Alvaro, 1880-19281
- Obscura2
- Oemler, Marie Conway, 1879-19321
- Ogden, Phebe Ann, 1790-18653
- Ogden, Uzal, 1744-18221
- Ogg, Florence Belle, 1879-19541
- Okamoto, Yoichi R. (Yoichi Robert), 1915-19851