List of Genera
- Orinophilus Cook, 1896
- Orphnaeus Meinert, 1870
- Orthothereua Verhoeff, 1905
- Ortognathus Folkmanova, 1958
- Orya Meinert, 1870
- Orygmadyla Hoffman & Pereira, 1997
- Osellaebius Matic, 1973
- Otocryptops Haase, 1887
- Otostigmus Porat, 1876
- Ottobius Chamberlin, 1952
- Pachymerellus Chamberlin, 1920
- Pachymerinus Silvestri, 1905
- Pachymerium C.L. Koch, 1847
- Pachymeroides Chamberlin, 1920
- Pagotaenia Chamberlin, 1915
- Paitobius Chamberlin, 1912
- Paleobius Chamberlin, 1952
- Pampibius Chamberlin, 1922
- Pandineum Chamberlin, 1955
- Paobius Chamberlin, 1916
- Paracryptops Pocock, 1891
- Paralamyctes Pocock, 1901
- Paraplanes Verhoeff, 1933
- Parascutigera Verhoeff, 1904
- Parorya Cook, 1896
