• Abanus Distant, 1909 accepted as Dieuches Dohrn, 1860
• Acanus Agassiz, 1834 (uncertain)
• Acinus Monterosato, 1884 accepted as Alvania Risso, 1826
• Actinus Fauvel, 1878
• Adenus † accepted as Adensu Popov & Rukavishnikova, 1986 † [Family: Adensuidae]
• Adenus Yokoyama, 1926 accepted as Adinus H. Adams & A. Adams, 1853 accepted as Bullia Gray, 1833 [Family: Nassariidae]
• Adesnus (uncertain)
• Adinus H. Adams & A. Adams, 1853 accepted as Bullia Gray, 1833
• Adonus Zaslavskij in Alonso-Zarazaga & Lyal, 1999
• Advenus Schools & Hedges, 2021
• Aedenus Voss, 1953
• Aednus Dallas, 1851 (uncertain)
• Aeternus Distant, 1918 (uncertain)
• Aganus Cabanis & Heine, 1863 (uncertain)
• Aglenus Erichson, 1845
• Agonus Bloch & Schneider, 1801
• Akonus Matsumura, 1929
• Alfenus Simon, 1902
• Alienus Bridwell, 1919 (uncertain) [Family: Hymenoptera (awaiting allocation)]
• Alienus Galileo & Martins, 2010 accepted as Hosticus Galileo, Rosa & Santos-Silva, 2020 [Family: Cerambycidae]
• Alienus Handlirsch, 1906 † [Family: Blattinopsidae]
• Alpenus Walker, 1855
• Alunus Hering, 1935
• Ananus Rubtzov, 1977 [Family: Marimermithidae]
• Ananus Sluiter, 1880 accepted as Holothuria Linnaeus, 1767 [Family: Holothuriidae]
• Angenus DeLong & Knull, 1971 accepted as Scaphoideus Uhler, 1888
• Anteonus Rafinesque, 1815 (unaccepted)
• Aocnus Kolenati, 1859 (uncertain)
• Aocnus Schoenherr, 1859 accepted as Sibinia Germar, 1817
• Apinus Necker ex Rydberg, 1905 (unaccepted)
• Apternus Swainson in Richardson, 1832 (uncertain)
• Aptinus Bonelli, 1810
• Arctenus Polotow & Jocqué, 2014
• Arrenus Field, 1904 accepted as Arrenurus Dugès, 1834
• Arunus Jaikishan Singh & Khan, 1997 [Family: Eulophidae]
• Arunus Sengupta & Pal, 1995 [Family: Monotomidae]
• Asemnus Agassiz, 1846 (unaccepted)
• Asinus Brisson, 1762 accepted as Equus Linnaeus, 1758
• Asinus Gray, 1824 accepted as Equus Linnaeus, 1758
• Asonus Yin, 1982 [Family: Acrididae]
• Asonus Yin, 1984 (uncertain) [Family: Orthoptera (awaiting allocation)]
• Astenus Dejean, 1833
• Asternus Guignot, 1931 accepted as Ilybius Erichson, 1832
• Astinus Stål, 1859 (uncertain)
• Ataenius Harold, 1867
• Atanus Oman, 1937
• Ateles Geoffroy, 1806
• Atelius Waterhouse, 1878
• Atemnus Berlese, 1884
• Atenesus Weise, 1923
• Atenia Gittenberger, 1968 [Family: Helicodontidae]
• Atenia W.J. Hooker & Arnott, 1839 accepted as Perideridia H.G.L. Reichenbach, 1837 [Family: Apiaceae]
• Atenizus Bates, 1867
• Aterpus Guerin-Meneville, 1834 accepted as Lithinus Klug, 1833
• Aterpus Schönherr, 1826 accepted as Aades Schönherr, 1823
• Athenes Fåhraeus, 1872 (uncertain)
• Atinus Horn, 1868
• Atranus Leconte, 1847
• Avernus Stål, 1866 (uncertain)
• Axenus Grote, 1873
• Axinus J. Sowerby, 1821
• Azanus Moore, 1881
• Batenus Motschoulsky, 1864 accepted as Platynus Bonelli, 1810
• Ctenus Mabille, 1906 (uncertain) [Family: Lepidoptera (awaiting allocation)]
• Ctenus Walckenaer, 1805 [Family: Ctenidae]
• Ptenus Kirby, 1882 (unaccepted)
• Stenus Latreille, 1796
• Tenus Michelotti, 1839 accepted as Venus Linnaeus, 1758