Occamus DISTANT, 1909 Þ Harpactorini, Harpactorinae
Ocrioessa BERGROTH, 1918 Þ Stenopodainae
Odontogonus BERGROTH, 1904 Þ Harpactorini, Harpactorinae
Oedemanota MILLER, 1957 Þ Harpactorini, Harpactorinae
Okondo SCHOUTEDEN, 1931 Þ Ectrichodiinae
Oncerotrachelus STAL, 1868 Þ Saicinae
Oncocephalus KLUG, 1830 Þ Stenopodainae
Onychomesa WYGODZINSKY, 1966 Þ Metapterini, Emesinae
Opisthacidius BERG, 1879 Þ Reduviinae
Opistoplatys WESTWOOD, 1834 Þ Opistoplatyini, Tribelocephalinae
Orianocoris VILLIERS, 1964 Þ Leistarchini, Emesinae
Orbella MALDONADO, 1987 Þ Harpactorini, Harpactorinae
Orthocnemis WESTWOOD, 1845 Þ Holoptilini, Holoptilinae
Orthunga DOHRN, 1859 Þ Leistarchini, Emesinae
Otiodactylus PINTO, 1927 Þ Stenopodainae
Oxythyreus WESTWOOD, 1841 Þ Macrocephalini, Phymatinae