• Ascidia Linnaeus, 1767
• Ascidia achimotae Millar, 1953
• Ascidia aclara Kott, 1952 accepted as Ascidia scaevola (Sluiter, 1904)
• Ascidia aculeata Alder, 1863 accepted as Ascidiella aspersa (Müller, 1776)
• Ascidia adhaerens Ritter, 1901 accepted as Ascidia callosa Stimpson, 1852
• Ascidia aenigmatica Nishikawa, 1986 accepted as Microgastra granosa (Sluiter, 1904)
• Ascidia affinis Hancock, 1870 accepted as Ascidiella aspersa (Müller, 1776)
• Ascidia aggregata Rathke, 1806 accepted as Dendrodoa aggregata Müller, 1776
• Ascidia ahodori Oka, 1927
• Ascidia albeola Lesueur, 1823 accepted as Ecteinascidia conklini Berrill, 1932
• Ascidia albida Alder & Hancock, 1848 accepted as Ascidiella aspersa (Müller, 1776)
• Ascidia alderi Alder & Hancock, 1912 accepted as Ascidia mentula Müller, 1776
• Ascidia alisea Monniot F. & Monniot C., 2006
• Ascidia alpha Tokioka, 1953
• Ascidia alterna Monniot C. & Monniot F., 1991
• Ascidia amoena Alder & Hancock, 1912 accepted as Ascidia conchilega Müller, 1776
• Ascidia amphora Agassiz, 1850 accepted as Molgula manhattensis (De Kay, 1843)
• Ascidia ampulloides Beneden, 1846 accepted as Molgula manhattensis (De Kay, 1843)
• Ascidia andamanensis Oka, 1915
• Ascidia aperta Sluiter, 1904 accepted as Ascidia archaia Sluiter, 1890
• Ascidia archaia Sluiter, 1890
• Ascidia arenosa Hartmeyer, 1898
• Ascidia armata Hartmeyer, 1906
• Ascidia aspera Brunetti, 2007
• Ascidia aspersa Müller, 1776 accepted as Ascidiella aspersa (Müller, 1776)
• Ascidia atra Lesueur, 1823 accepted as Phallusia nigra Savigny, 1816
• Ascidia aurantium Pallas, 1787 accepted as Halocynthia aurantium (Pallas, 1787)
• Ascidia aurata Quoy & Gaimard, 1834 accepted as Polycarpa aurata (Quoy & Gaimard, 1834)
• Ascidia aurora Quoy & Gaimard, 1834 (uncertain > nomen dubium)
• Ascidia austera Sluiter, 1904
• Ascidia australiensis Hartmeyer, 1927 accepted as Ascidia latesiphonica Hartmeyer, 1922
• Ascidia australis Quoy & Gaimard, 1834 accepted as Pyura australis (Quoy & Gaimard, 1834)
• Ascidia aximensis Millar, 1953
• Ascidia azurea Monniot F. & Monniot C., 1996
• Ascidia bathybia Hartmeyer, 1922
• Ascidia bifissa Sluiter, 1895
• Ascidia bisulca Sluiter, 1904 accepted as Ascidia sydneiensis Stimpson, 1855
• Ascidia bocatorensis Bonnet & Rocha, 2011
• Ascidia caguayensis Millar & Goodbody, 1974 accepted as Phallusia caguayensis (Millar & Goodbody, 1974)
• Ascidia calcata Stimpson, 1855 (uncertain > nomen dubium)
• Ascidia californica Ritter & Forsyth, 1917 accepted as Ascidia ceratodes (Huntsman, 1912)
• Ascidia callosa Stimpson, 1852
• Ascidia canaliculata Heller, 1878
• Ascidia canina Mueller, 1776 accepted as Ciona intestinalis (Linnaeus, 1767)
• Ascidia cannelata Oken, 1820
• Ascidia capillata Sluiter, 1887
• Ascidia carnea Agassiz, 1850 accepted as Dendrodoa carnea (Agassiz, 1850)
• Ascidia cartilaginosa [Renier], [1804] (unaccepted > unavailable name)
• Ascidia caudata Heller, 1878
• Ascidia cavernosa Lesueur, 1823 accepted as Microcosmus exasperatus Heller, 1878
• Ascidia celtica Monniot C., 1969
• Ascidia ceratodes (Huntsman, 1912)
• Ascidia challengeri Herdman, 1882
• Ascidia charcoti Sluiter, 1905 accepted as Ascidia challengeri Herdman, 1882
• Ascidia citrina Nishikawa & Tokioka, 1975
• Ascidia clavata Mueller, 1776 accepted as Boltenia ovifera (Linnaeus, 1767)
• Ascidia clavata Pallas, 1774 accepted as Styela clavata (Pallas, 1774)
• Ascidia claviformis Lesueur, 1823 (uncertain > nomen dubium)
• Ascidia clementea Ritter, 1907
• Ascidia coerulea Quoy & Gaimard, 1834 accepted as Asterocarpa coerulea (Quoy & Gaimard, 1834)
• Ascidia colleta Monniot C. & Monniot F., 1970
• Ascidia collini Bonnet & Rocha, 2011
• Ascidia columbiana (Huntsman, 1912)
• Ascidia complanata Fabricius, 1780 accepted as Ascidia prunum Müller, 1776
• Ascidia compressa Rathke, 1806 accepted as Ascidia obliqua Alder, 1863
• Ascidia compta Sluiter, 1898 accepted as Ascidia sydneiensis Stimpson, 1855
• Ascidia conchilega Müller, 1776
• Ascidia conifera (Hartmeyer, 1911)
• Ascidia corallicola Bonnet & Rocha, 2011
• Ascidia corelloides (Van Name, 1924) accepted as Ascidia archaia Sluiter, 1890
• Ascidia corelloides var. mediterranea Pérès, 1959 accepted as Ascidia mediterranea Pérès, 1959
• Ascidia correi Monniot C., 1970
• Ascidia corrugata Mueller, 1776 accepted as Ciona intestinalis (Linnaeus, 1767)
• Ascidia crassa Alder & Hancock, 1912 accepted as Ascidia mentula Müller, 1776
• Ascidia cristata Risso, 1826 accepted as Ascidiella aspersa (Müller, 1776)
• Ascidia curvata (Traustedt, 1882)
• Ascidia cuviera Delle Chiaje, 1841 accepted as Styela plicata (Lesueur, 1823)
• Ascidia cuvieri Delle Chiaje, 1841 accepted as Styela plicata (Lesueur, 1823)
• Ascidia cylindracea Herdman, 1880 (uncertain > nomen dubium)
• Ascidia decemplex Sluiter, 1890 accepted as Ascidia kreagra Sluiter, 1895
• Ascidia decepta Kott, 1985
• Ascidia depressa Alder & Hancock, 1912 accepted as Ascidia conchilega Müller, 1776
• Ascidia depressiuscula Heller, 1878
• Ascidia despecta Herdman, 1880
• Ascidia diaphanea Quoy & Gaimard, 1834 accepted as Ciona intestinalis (Linnaeus, 1767)
• Ascidia dijmphniana (Traustedt, 1886)
• Ascidia diplozoon Sluiter, 1887 accepted as Ascidia sydneiensis Stimpson, 1855
• Ascidia dispar Ärnbäck, 1938 accepted as Ascidia challengeri Herdman, 1882
• Ascidia divisa Sluiter, 1898 accepted as Ascidia sydneiensis Stimpson, 1855
• Ascidia donnani Herdman, 1906 accepted as Ascidia sydneiensis Stimpson, 1855
• Ascidia dorsalis Monniot C., 1987 accepted as Ascidia liberata Sluiter, 1887
• Ascidia dorsata Meenakshi & Renganathan, 1999
• Ascidia echinata Linnaeus, 1767 accepted as Boltenia echinata (Linnaeus, 1767)
• Ascidia eiseni Michaelsen, 1923 accepted as Ascidia ceratodes (Huntsman, 1912)
• Ascidia elliptica Alder & Hancock, 1848 accepted as Ascidiella aspersa (Müller, 1776)
• Ascidia elongata Alder & Hancock, 1912 accepted as Ascidia conchilega Müller, 1776
• Ascidia empheres Sluiter, 1895
• Ascidia escabanae Monniot C., 1998
• Ascidia expansa Kiaer, 1893 accepted as Ascidiella aspersa (Müller, 1776)
• Ascidia falcigera Herdman, 1880 accepted as Ascidia obliqua Alder, 1863