• Acanthiella chaetonotoides Rieger & Sterrer, 1975: Turbellaria
• Acanthomacrostomum gerlachi Ax, 1971: Turbellaria
• Acanthomacrostomum spiculiferum Papi & Swedmark, 1959: Turbellaria
• Acanthopseudomonocelis mirabilis Curini-Galletti & Cannon, 1995: Turbellaria
• Acanthozoon albopapillosum Hyman, 1959: Turbellaria
• Acanthozoon albopunctatum Prudhoe, 1978: Turbellaria
• Acanthozoon alderi (Collingwood, 1876): Turbellaria
• Acanthozoon allmani (Collingwood, 1876): Turbellaria
• Acanthozoon aranfaibo Cuadrado, Moro & Norena, 2017: Turbellaria
• Acanthozoon armatum (Kelaart, 1858): Turbellaria
• Acanthozoon auropunctatum (Kelaart, 1858): Turbellaria
• Acanthozoon boehmigi (Stummer-Traunfels, 1895): Turbellaria
• Acanthozoon fuscobulbosum Dixit, Sivaperuman & Raghunathan, 2018: Turbellaria
• Acanthozoon hispidum (Du Bois-Reymond Marcus, 1955): Turbellaria
• Acanthozoon indicum (Plehn, 1896): Turbellaria
• Acanthozoon lepidum (Heath & McGregor, 1912): Turbellaria
• Acanthozoon maculosum (Pearse, 1938): Turbellaria
• Acanthozoon marginatum (Plehn, 1896): Turbellaria
• Acanthozoon obscurum (Stummer-Traunfels, 1895): Turbellaria
• Acanthozoon ovale (Schmarda, 1859): Turbellaria
• Acanthozoon papilionis (Kelaart, 1858): Turbellaria
• Acanthozoon plehni (Laidlaw, 1902): Turbellaria
• Acanthozoon semperi (Stummer-Traunfels, 1895): Turbellaria
• Acerotisa alba Freeman, 1933: Turbellaria
• Acerotisa arctica Hyman, 1953: Turbellaria
• Acerotisa baiae Hyman, 1940: Turbellaria
• Acerotisa bituna Marcus, 1947: Turbellaria
• Acerotisa californica Hyman, 1953: Turbellaria
• Acerotisa inconspicua (Lang, 1884): Turbellaria
• Acerotisa langi (Heath & McGregor, 1912): Turbellaria
• Acerotisa leuca Marcus, 1947: Turbellaria
• Acerotisa maculata (Hallez, 1905): Turbellaria
• Acerotisa nationalis (Plehn, 1896): Turbellaria
• Acerotisa notulata (Bosc, 1802): Turbellaria
• Acerotisa ochotensis Tokinova, 2015: Turbellaria
• Acerotisa typhla (Bock, 1913): Turbellaria
• Acestoplana raffaelei (Ranzi, 1928): Turbellaria
• Acholades asteris Hickman & Olsen, 1955: Turbellaria
• Acirrostylus poncedeleoni Van Steenkiste, Volonterio, Schockaert & Artois, 2008: Turbellaria
• Acmostomum (Acmostomum) dioicum Metschnikoff, 1865: Turbellaria
• Acmostomum (Tuilica) evelina Marcus, 1951: Turbellaria
• Acmostomum canarium Marcus, 1947: Turbellaria
• Acmostomum denticulatum Schmarda, 1859: Turbellaria
• Acmostomum dioicum Metschnikoff, 1865: Turbellaria
• Acmostomum mecznikowski Kulinitch, 1973: Turbellaria
• Acmostomum obscurum (An der Lan, 1936): Turbellaria
• Acrochordonoposthia apopera Reisinger, 1924: Turbellaria
• Acrochordonoposthia conica Reisinger, 1924: Turbellaria
• Acrochordonoposthia diademula Schwank, 1980: Turbellaria
• Acrochordonoposthia nemoralis Reisinger, 1924: Turbellaria
• Acrochordonoposthia ophiocephala Reisinger, 1924: Turbellaria
• Acrochordonoposthia ramolia An der Lan, 1958: Turbellaria
• Acrochordonoposthia reversa Reisinger, 1924: Turbellaria
• Acrochordonoposthia robusta Luther, 1963: Turbellaria
• Acrochordonoposthia vandeputae Houben, Proesmans & Artois, 2014: Turbellaria
• Acromyadenium maroccanum de Beauchamp, 1931: Turbellaria
• Acrorhynchides caledonicus (Claperede, 1861) Strand, 1928: Turbellaria
• Acrorhynchides canaliculatus Armonies, 2018: Turbellaria
• Acrorhynchides robustus (Karling, 1931) Strand, 1928: Turbellaria
• Acrorhynchides styliferus Schockaert & Karling, 1975: Turbellaria
• Acrumena massiliensis Brunet, 1965: Turbellaria
• Aculeorhynchus glandulis Schilke, 1969: Turbellaria
• Adenocerca bresslaui Reisinger, 1924: Turbellaria
• Adenocerca clinopharynx Reisinger, 1924: Turbellaria
• Adenocerca minima Kolasa, 1981: Turbellaria
• Adenocerca teshirogii Kolasa, 1981: Turbellaria
• Adenodactyloplana uruguayensis Bulnes, Faubel & Ponce de Leon, 2003: Turbellaria
• Adenopharynx mitrabursalis Ehlers, 1972: Turbellaria
• Adenoplana evelinae Marcus, 1950: Turbellaria
• Adenoplana obovata (Schmarda, 1859): Turbellaria
• Adenoplana platae Hyman, 1955: Turbellaria
• Adenoplea armata Reisinger, 1924: Turbellaria
• Adenoplea inermis Reisinger, 1924: Turbellaria
• Adenoplea meridionalis Kolasa, 1981: Turbellaria
• Adenoplea nanus Sayre & Wergen, 1994: Turbellaria
• Adenoplea paraproxenetes Reisinger, 1924: Turbellaria
• Adenoplea perigraptopera Reisinger, 1924: Turbellaria
• Adenoplea pinguis Reisinger, 1924: Turbellaria
• Adenoplea reisingeri Houben, Proesmans & Artois, 2015: Turbellaria
• Adenoplea weyeri An der Lan, 1955: Turbellaria
• Adenorhynchus balticus Meixner, 1938: Turbellaria
• Adenorhynchus compositus Armonies, 2020: Turbellaria
• Adinoplana alerna Almeida & Carbayo, 2023: Turbellaria
• Adinoplana nahuta Almeida & Carbayo, 2023: Turbellaria
• Aegira annabellae Willems, Artois, Vermin, Backeljau & Schockaert, 2005: Turbellaria
• Alaoplana lanceolata (Grube, 1872): Turbellaria
• Alaoplana sublanceolata (Livanov & Porfirjeva, 1964): Turbellaria
• Alaskaplana velox Ax & Armonies, 1990: Turbellaria
• Alcha evelinae Marcus, 1949: Turbellaria
• Alcha sinensis Wang & Hu, 2019: Turbellaria
• Alchoides alchoides Willems, Schockaert & Artois, 2006: Turbellaria
• Alchoides dittmannae Willems, Schockaert & Artois, 2006: Turbellaria
• Alexlutheria acrosiphoniae Karling, 1956: Turbellaria
• Alexlutheria psammophila Ax, 2008: Turbellaria
• Alloeostyliphora mirabilis Curini-Galletti, Oggiano & Casu, 2001: Turbellaria
• Allogenus kerguelenense (Hyman, 1958): Turbellaria
• Allogenus sluysi Volonterio & Berwin, 2013: Turbellaria
• Alloioplana aulica (Marcus, 1947): Turbellaria
• Alloioplana delicata Plehn, 1896: Turbellaria
• Alloioplana stylifera (Hyman, 1953): Turbellaria