History of Astronomy: Persons (O)
- Oberth, Hermann Julius (1894-1989)
- Odierna [Hodierna; Adierna], Gioanbatista [Giovan/Giovanni Battista] (1597-1660)
- Oenopides of Chios (c. 490 BC - c. 420 BC)
- Öhman, Karl Yngve (1903-1988)
- Oja, Tarmo (20th c.)
- Oken, Lorenz (1779-1851)
- Olbers, Heinrich Wilhelm (1758-1840)
- Oliver, Bernard M. [Barney] (1916?-1995)
- Omar Khayyam (1048-1122): see al-Khayyam
- Oort, Jan Hendrik (1900-1992)
- Öpik (Opik), Ernst Julius (1893-1985)
- Oppenheim, Samuel (1857-1928)
- Oppenheimer, Julius Robert (1904-1967)
- Oppolzer, Theodor von (1841-1886)
- Oresme, Nicole d' (1320-1382)
- Oriani, Barnaba [Barnabé] (1752-1832)
- Osiander, Andreas (1498-1552)
- Osipovskij [Osipovsky], Timofej [Timofei] Fedorovich (1765-1832)
- Osterbrock, Donald Edward (b. 1924)
- Oughtred [Owtred], William (1575-1660)
- Ozanam, Jacques (1640-1717/18)
Wolfgang R. Dick.
Created: 16 Jan 1995.
Latest update: 20 Feb 2002