- Oakeley, Herbert Stanley (1830-1903)
- Oberthür, Karl (1819-1895)
- Ochs, Siegfried (1858-1929)
- Ochsenkhun, Sebastian (1521-1574)
- Oesten, Theodor (1813-1870)
- Oestreich, Carl (1800-1840)
- Offenbach, Jacques (1819-1880)
- Oginsky, Michael Kleophas (1765-1831)
- O´Neill, Norman Houston (1875-1934)
- Onslow, Georges (1784-1852)
- Osborne, George Alexander (1806-1893)
- Othegraven, August von (1864-1946)
- Otto, Ernst Julius (1804-1877)