The Rotoitidae are a very small family of rare, relictual parasitic wasps in the superfamily Chalcidoidea. Only two species are known, each in its own genus, one from New Zealand and one from Chile. They are the most recently discovered family of chalcidoids, though they may be the most ancient lineage, and little is known about their biology. Females of the Chilean species, Chiloe micropteron, have their wings reduced to tiny bristles.
Features of their anatomy, including very "primitive" wing venation, have led researchers to believe the rotoitids may be very close to the base of the chalcidoid family tree, close to the Mymaridae.