The subfamily Diapriinae (Diapriidae: Proctotrupoidea) in the New World is reviewed at the supra specific level. Three tribes and 52 genera are recognized. Sixteen new genera are proposed: Apopria (Diapriini), Avoca (Diapriini), Chilomicrus (Spilomicrini), Cruzium (Diapriini), Doddius (Spilomicrini), Eladio (Diapriini), Epomium (Spilomicrini), Ferrugenus (Spilomicrini), Hansona (Diapriini), Leucopria (Diapriini), Mimopriella (Diapriini), Omopria (Diapriini), Ortona (Psilini), Peckidium (incertae sedis) Psychopria (Diapriini), and Turripria (Diapriini). The following new species are described: Apopria coveri ♀ (USA), Asolenopsia gibba ♀ (Costa Rica), Avoca collaris ♀ (USA), Chilomicrus pecki ♂ (Chile), Cruzium amphorale ♀ (Costa Rica), Eladio cruzi ♀ (Costa Rica), Epomium cicatrix ♀ (Chile), Ferrugenus chilensis ♀ (Chile), Hansona pauli ♀ (Costa Rica), Leucopria cylindricornis ♀ (Ecuador, Costa Rica), Omopria brevipalpis ♀ (Brazil), Ortona hansoni ♀ (Costa Rica), Peckidium enigmaticum ♀ (Antilles, Central and South America, West Africa, Philippines), Psychopria hoguei ♂ (Costa Rica), Turripria woldai ♀ (Panama). New generic synonymies are proposed: Acanthopria Ashmead (=Adelioneiva Fischer), Asolenopria Kieffer (=Euplacopria Ferrière), Bruchopria Kieffer (=Aulatopria Brèthes), Doliopria Kieffer (=Martinica Risbec), Megaplastopria Ashmead (=Xyalopria Kieffer), Notoxoides Ashmead (=Psilogasteroides Brèthes), Pentapria Kieffer (=Antipapria Fabritius, Bakeria Kieffer, Plutopria Kieffer, Spilomicrinus Ogloblin), Spilomicrus Westwood (=Hoplopria Ashmead, Linkiola Kieffer) , Szelenyiopria Fabritius (=Gymnopria Loiácono). New combinations are proposed: Aulatopria tucumana Brèthes to Bruchopria, Bakeria rugosa Dodd to Doddius, Gymnopria lucens Loiacono to Szelenyiopria, Mimopria pentatoma Borgmeier and Mimopria splendens