• Octopus Cuvier, 1798
• Octopus (Abdopus) Norman & Finn, 2001 accepted as Abdopus Norman & Finn, 2001
• Octopus (Abdopus) aculeatus A. d'Orbigny, 1834 accepted as Abdopus aculeatus (A. d'Orbigny, 1834)
• Octopus (Abdopus) capricornicus Norman & Finn, 2001 accepted as Abdopus capricornicus (Norman & Finn, 2001)
• Octopus (Macroctopus) G. C. Robson, 1928 accepted as Macroctopus G. C. Robson, 1928
• Octopus (Macrotritopus) Grimpe, 1922 accepted as Macrotritopus Grimpe, 1922
• Octopus (Macrotritopus) danae Joubin & G. C. Robson, 1929 accepted as Scaeurgus unicirrhus (Delle Chiaje, 1841)
• Octopus (Macrotritopus) equivocus G. C. Robson, 1929 accepted as Macrotritopus equivocus (G. C. Robson, 1929)
• Octopus (Octopus) Cuvier, 1798 represented as Octopus Cuvier, 1798
• Octopus (Octopus) joubini G. C. Robson, 1929 represented as Octopus joubini G. C. Robson, 1929
• Octopus (Octopus) teuthoides G. C. Robson, 1929 (uncertain > nomen dubium)
• Octopus (Philonexis) A. d'Orbigny, 1835 accepted as Tremoctopus delle Chiaje, 1830
• Octopus (Philonexis) atlanticus A. d'Orbigny, 1835 accepted as Tremoctopus violaceus Delle Chiaje, 1830
• Octopus (Philonexis) eylais A. d'Orbigny, 1834 accepted as Cranchia scabra Leach, 1817
• Octopus (Philonexis) minimus A. d'Orbigny, 1835 accepted as Argonauta hians [Lightfoot], 1786
• Octopus (Philonexis) quoyanus A. d'Orbigny, 1834 accepted as Tremoctopus violaceus Delle Chiaje, 1830
• Octopus abaculus Norman & Sweeney, 1997 accepted as Abdopus abaculus (Norman & Sweeney, 1997)
• Octopus aculeatus A. d'Orbigny, 1834 accepted as Abdopus aculeatus (A. d'Orbigny, 1834)
• Octopus adamsi Benham, 1944 accepted as Octopus huttoni (Benham, 1943) accepted as Robsonella huttoni Benham, 1943
• Octopus aegina J. E. Gray, 1849 accepted as Amphioctopus aegina (J. E. Gray, 1849)
• Octopus alatus (Sasaki, 1920) (uncertain > taxon inquirendum)
• Octopus alberti Joubin, 1895 (uncertain > nomen dubium)
• Octopus albus Rafinesque, 1814 accepted as Octopus vulgaris Cuvier, 1797
• Octopus alderii Vérany, 1851 accepted as Callistoctopus macropus (Risso, 1826)
• Octopus aldrovandi delle Chiaje, 1830 accepted as Eledone cirrhosa (Lamarck, 1798)
• Octopus alecto S. S. Berry, 1953
• Octopus alphaeus [sic] accepted as Callistoctopus alpheus (Norman, 1993)
• Octopus alpheus Norman, 1993 accepted as Callistoctopus alpheus (Norman, 1993)
• Octopus amboinensis Brock, 1887 (uncertain > nomen dubium)
• Octopus americanus Froriep, 1806
• Octopus apollyon (S. S. Berry, 1912) accepted as Enteroctopus dofleini (Wülker, 1910)
• Octopus aranea A. d'Orbigny, 1834 (uncertain > taxon inquirendum)
• Octopus araneoides Taki, 1964 (uncertain > taxon inquirendum)
• Octopus arborescens (Hoyle, 1904) (uncertain > taxon inquirendum)
• Octopus arcticus Prosch, 1849 accepted as Bathypolypus arcticus (Prosch, 1849)
• Octopus areolatus de Haan, 1839-1841 accepted as Amphioctopus fangsiao (d'Orbigny [in A. Férussac & d'Orbigny], 1839-1841)
• Octopus argus Krauss, 1848
• Octopus aspilosomatis Norman, 1993 accepted as Callistoctopus aspilosomatis (Norman, 1993)
• Octopus australis Hoyle, 1885
• Octopus backerii A. d'Orbigny, 1826 accepted as Octopus bakerii A. d'Orbigny, 1826 accepted as Octopus americanus Froriep, 1806
• Octopus bairdii A. E. Verrill, 1873 accepted as Bathypolypus bairdii (A. E. Verrill, 1873)
• Octopus bakerii A. d'Orbigny, 1826 accepted as Octopus americanus Froriep, 1806
• Octopus balboai G. L. Voss, 1971
• Octopus bandensis Hoyle, 1885 (uncertain > nomen dubium)
• Octopus berenice Gray, 1849
• Octopus bermudensis Hoyle, 1885 accepted as Callistoctopus furvus (A. Gould, 1852)
• Octopus berrima Stranks & Norman, 1992
• Octopus bimaculatus A. E. Verrill, 1883
• Octopus bimaculoides Pickford & McConnaughey, 1949
• Octopus bitentaculatus Risso, 1854 accepted as Octopus vulgaris Cuvier, 1797
• Octopus bocki Adam, 1941
• Octopus brevipes A. d'Orbigny, 1835 (uncertain > nomen dubium)
• Octopus brevitentaculatus Blainville, 1826 accepted as Octopus vulgaris Cuvier, 1797
• Octopus briareus G. C. Robson, 1929
• Octopus brocki Ortmann, 1888 accepted as Amphioctopus fangsiao (d'Orbigny [in A. Férussac & d'Orbigny], 1839-1841)
• Octopus bulbus Norman, 2001
• Octopus bunurong Stranks, 1990 accepted as Callistoctopus bunurong (Stranks, 1990)
• Octopus burryi G. L. Voss, 1950 accepted as Amphioctopus burryi (G. L. Voss, 1950)
• Octopus caerulescens Blainville, 1826 (uncertain > nomen dubium)
• Octopus californicus (S. S. Berry, 1911)
• Octopus campbelli (E. A. Smith, 1902) accepted as Robsonella campbelli (E. A. Smith, 1902)
• Octopus capensis Souleyet, 1852 (uncertain > nomen dubium)
• Octopus carenae Vérany, 1839 accepted as Ocythoe tuberculata Rafinesque, 1814
• Octopus carolinensis A. E. Verrill, 1884 accepted as Amphioctopus carolinensis (A. E. Verrill, 1884)
• Octopus cassiopea Gray, 1849 accepted as Octopus vulgaris Cuvier, 1797
• Octopus cassiopeia Gray, 1849 accepted as Octopus cassiopea Gray, 1849 accepted as Octopus vulgaris Cuvier, 1797
• Octopus catenulatus R. A. Philippi, 1844 accepted as Ocythoe tuberculata Rafinesque, 1814
• Octopus cephea Gray, 1849 (uncertain > taxon inquirendum)
• Octopus chierchiae Jatta, 1889
• Octopus chromatus Heilprin, 1888 accepted as Callistoctopus furvus (A. Gould, 1852)
• Octopus chuni Grimpe, 1922 (uncertain > taxon inquirendum)
• Octopus ciliatus Rang, 1837 (uncertain > taxon inquirendum)
• Octopus cirrhosus Lamarck, 1798 accepted as Eledone cirrhosa (Lamarck, 1798)
• Octopus cocco Risso, 1854 accepted as Scaeurgus unicirrhus (Delle Chiaje, 1841)
• Octopus cocco Vérany, 1846 accepted as Pteroctopus tetracirrhus (Delle Chiaje, 1830)
• Octopus coerulescentes Fra Piero, 1895 accepted as Octopus vulgaris Cuvier, 1797
• Octopus communis Park, 1885 accepted as Macroctopus maorum (F. W. Hutton, 1880)
• Octopus conispadiceus (Sasaki, 1917)
• Octopus cordiformis Quoy & Gaimard, 1832 accepted as Pinnoctopus cordiformis (Quoy & Gaimard, 1832)
• Octopus cornutus Owen, 1881 (uncertain > nomen dubium)
• Octopus cuvieri A. d'Orbigny, 1826 accepted as Callistoctopus lechenaultii (A. d'Orbigny, 1826)
• Octopus cyanea Gray, 1849
• Octopus cyanea var. gracilis G. C. Robson, 1929 accepted as Octopus cyanea Gray, 1849
• Octopus dana G. C. Robson, 1929 accepted as Octopus defilippi var. dama G. C. Robson, 1929 accepted as Macrotritopus defilippi (Vérany, 1851)
• Octopus defilippi Vérany, 1851 accepted as Macrotritopus defilippi (Vérany, 1851)
• Octopus defilippi var. dama G. C. Robson, 1929 accepted as Macrotritopus defilippi (Vérany, 1851)
• Octopus didynamus Rafinesque, 1814 accepted as Callistoctopus macropus (Risso, 1826)
• Octopus dierythraeus Norman, 1993 accepted as Callistoctopus dierythraeus (Norman, 1993)
• Octopus digueti Perrier & Rochebrune, 1894 accepted as Paroctopus digueti (Perrier & Rochebrune, 1894)
• Octopus diminutus Kaneko & Kubodera, 2008
• Octopus djinda Amor, 2021
• Octopus dofleini (Wülker, 1910) accepted as Enteroctopus dofleini (Wülker, 1910)
• Octopus dollfusi G. C. Robson, 1928 accepted as Amphioctopus aegina (J. E. Gray, 1849)
• Octopus dubius Souleyet, 1852 (uncertain > nomen dubium)
• Octopus duplex Hoyle, 1885 accepted as Octopus superciliosus Quoy & Gaimard, 1832
• Octopus elegans Brock, 1887 (uncertain > nomen dubium)
• Octopus equivocus G. C. Robson, 1929 accepted as Macrotritopus equivocus (G. C. Robson, 1929)
• Octopus ergasticus P. Fischer & H. Fischer, 1892 accepted as Bathypolypus ergasticus (P. Fischer & H. Fischer, 1892)
• Octopus eudora J. E. Gray, 1849 accepted as Octopus americanus Froriep, 1806
• Octopus exannulatus Norman, 1993 accepted as Amphioctopus exannulatus (Norman, 1993)