List of Genera
- Malochora Chamberlin, 1941
- Maoriella Attems, 1903
- Marshallopus Verhoeff, 1937
- Marsikomerus Attems, 1938
- Mayobius Chamberlin, 1943
- Mecistauchenus Brölemann, 1907
- Mecistocephalus Newport, 1843
- Mecophilus Silvestri, 1909
- Megalacrus Attems, 1953
- Megethmus Cook, 1896
- Meinertophilus Silvestri, 1898
- Mesobius Chamberlin, 1951
- Mesobothrus Folkmanova, 1940
- Mesocanthus Meinert, 1870
- Mesogeophilus Verhoeff, 1901
- Mesoleptodon Chamberlin, 1920
- Mesoschendyla Attems, 1909
- Metalithobius Chamberlin, 1910
- Metaxythus Crabill, 1968
- Mexicobius Chamberlin, 1915
- Mexiconyx Chamberlin, 1922
- Mexicotarsus Verhoeff, 1934
- Microthereua Verhoeff, 1905
- Mimops Kraepelin, 1903
- Mixophilus Silvestri, 1929
