• Gdowia Yanishevsky, 1950 †
• Grewia Linnaeus, 1753
• Grobina Dubois, 1987 (uncertain)
• Grobya J. Lindley, 1835
• Gromia Dujardin, 1835
• Gronias Cope, 1864 accepted as Ameiurus Rafinesque, 1820
• Grooca Surenshan & Narendran, 1997 (uncertain)
• Grossia Alberti, 1960 † (uncertain) [Family: Trilobita (awaiting allocation)]
• Grossia Womersley, 1954 accepted as Chyzeria Canestrini, 1897 [Family: Chyzeriidae]
• Grotea Cresson, 1864 [Family: Ichneumonidae]
• Grotea H. Wang, J. Blanchard & D.L. Dilcher, 2013 † [Family: Bignoniaceae]
• Grotea Moore, 1866 accepted as Sebastia Kirby, 1892 [Family: Erebidae]
• Grotea Möschler, 1876 accepted as Podosesia Möschler, 1879 [Family: Sesiidae]
• Grotea Theobald, 1868 [Family: Colubridae]
• Groutia J.B.A. Guillemin & Perrottet in J.B.A. Guillemin, Perrottet & A. Richard, 1831 (uncertain) [Family: Opiliaceae]
• Groutia V.F. Brotherus in Engler & Prantl, 1905 (unaccepted) [Family: Cryphaeaceae]
• Grovea A. Schmidt ex Van Heurck, 1896 †
• Groveia Karling, 1980
• Grunowia Rabenhorst, 1864
• Rowia Deiss, 1939 †