- Ochetus morrisi (FORBES, 1849)
- Offaster cf. leymeriei (COTTEAU, 1887)
- Offaster pilula (LAMARCK, 1816)
- Offaster pomeli (MUNIER CHALMAS, 1884)
- Oligophyma oranensis ? (POMEL, 1887)
- Oligopygus haldemani (CONRAD, 1850)
- Oligopygus phelani (KIER, 1967)
- Oligopygus rotundus (COOKE, 1942)
- Oligopygus wetherbyi (DE LORIOL, 1888)
- Oolopygus pyriformis (LESKE , 1778)
- Opissaster cf. baylei (COTTEAU, 1877)
- Orbispala occultoforma (IRWIN, 1995) - Mioceno -
- Orbispala occultoforma (IRWIN, 1995) - Oligoceno -
- Orthaster dagestanensis (MOSKVIN, 1982)
- Oriolampas michelini (COTTEAU in COTTEAU & LEYMERIE, 1856)
- Ortholophus pulchellus (BITTNER, 1892)
- Ortholophus woodsi (LAUBE, 1869)
- Orthopsis granularis (AGASSIZ, 1846)
- Orthopsis miliaris (d'ARCHIAC, 1837)
- Orthopsis ovata (COQUAND, 1862)
- Ova saheliensis (POMEL, 1887)
- Ovulaster auberti (GAUTHIER, 1892)
- Ovulaster gauthieri (COTTEAU, 1884)
- Ovulaster obtusus (COTTEAU & BLAYAC, 1909)