• Acuaria Bremser, 1811 [Family: Acuariidae]
• Acuaria Quenstedt, 1856 † (uncertain) [Family: Cephalopoda (awaiting allocation)]
• Acuaria Zakrzewski, 1886 (uncertain) [Family: Mollusca (awaiting allocation)]
• Acularia Rafinesque, 1840 (uncertain)
• Adriaria Pallary, 1917 (uncertain)
• Aguiaria Ducke, 1935
• Aguilaria Retana-Salazar & Soto-Rodríguez, 2007 accepted as Dioclesianothrips Retana-Salazar & Soto-Rodriguez, 2007 accepted as Karnyothrips Watson, 1923 [Family: Phlaeothripidae]
• Aguilaria Taylor & Wells, 1994 [Family: Pseudomelatomidae]
• Alliaria Heister ex Fabricius, 1759 [Family: Brassicaceae]
• Alliaria O. Kuntze, 1891 accepted as Dysoxylum Blume, 1825 [Family: Meliaceae]
• Alniaria K. Rushforth, 2018
• Amularia Brera, 1811 accepted as Setaria Viborg, 1795
• Aniaria Gistel, 1850 accepted as Aniaria Horn, 1893 accepted as Aniara Hope, 1838
• Aniaria Horn, 1893 accepted as Aniara Hope, 1838
• Anularia Tapparone-Canefri, 1889 accepted as Annularia Schumacher, 1817
• Apiaria Germar in Münster, 1842 † (uncertain)
• Apiaria Germar, 1839 (uncertain)
• Aquaria Perry, 1811 accepted as Penicillus Bruguière, 1789 accepted as Verpa Röding, 1798
• Aquartia N.J. Jacquin, 1760 accepted as Solanum Linnaeus, 1753
• Aquilaria Lamarck, 1783 [Family: Thymelaeaceae]
• Aquilaria Taylor & Wells, 1994 (uncertain) [Family: Turridae]
• Aquilia Schinz in Cuvier, 1822 (unaccepted)
• Aquillia Reichenbach, 1828 (unaccepted)
• Aquimarina Nedashkovskaya, Kim, Lysenko, Frolova, Mikhailov, Lee & Bae, 2005
• Aquirra Muir, 1918 (unaccepted)
• Atubaria Sato, 1936 (uncertain > nomen dubium)
• Aularia Haeckel, 1887
• Auraria Middleton & Dewar, 2004 †