As part of comprehensive studies on the world fauna of microgastrine parasitoid wasps (Hymenoptera: Braconidae) 17 new genera and 29 new species are described from the Afrotropical, Australasian, Neotropical and Oriental regions. The number of extant genera of Microgastrinae is increased by 21% and currently stands at 81. It is anticipated that more genera will be described in the near future, when phylogenetic studies of the group are advanced. The new taxa showcase unusual morphological traits such as atypical head and mouth part modifications, presence of partial occipital and epicnemial carinae, propodeum carination patterns, hind wing venation, trochantellus shape, tarsal claws, sculpture and shape of the first two metasomal tergites, and ovipositor teeth; in some cases, they also represent some of the largest species known in the subfamily. For every new genus putative autapomorphies, morphological diagnostic features, and DNA barcodes (whenever available) are presented, as well as brief discussions of some informal groupings of genera in the subfamily. However, no attempt is made to reassess the phylogeny of the entire Microgastrinae, as that will require more comprehensive analyses beyond the scope of the present work. The following 17gen. n., authored by Fernandez-Triana, are described:Agupta,Austinicotesia,Billmasonius,Carlmuesebeckius,Gilbertnixonius,Janhalacaste,Jenopappius,Jimwhitfieldius,Kotenkosius,Markshawius,Ohenri,Qrocodiledundee,Silvaspinosus,Tobleronius,Ungunicus,YpsilonigasterandZachterbergius. The following 29sp. n., authored by Fernandez-Triana and Boudreault, are described:Aguptadanyi,Aguptajeanphilippei,Aguptaraymondi,Aguptasolangeae,Austinicotesiaindonesiensis,Austinicotesiapapuanus,Billmasoniuscienci,Carlmuesebeckiussmithsonian,Gilbertnixoniusbiem,Janhalacastedanieli,Janhalacasteguanacastensis,Janhalacastewinnieae,Jenopappiusmagyarmuzeum,Jimwhitfieldiusjamesi,Jimwhitfieldiussydneyae,Kotenkosiustricarinatus,Markshawiuserucidoctus,Markshawiusfrancescae,Markshawiusthailandensis,Ohenrigouletorum,Qrocodiledundeeoutbackense,Silvaspinosusvespa,Tobleroniusorientalis,Ungunicusvietnamensis,Ypsilonigasternaturalis,Ypsilonigastersharkeyi,Ypsilonigastertiger,Ypsilonigasterzuparkoi, andZachterbergiustenuitergum. The following fourcomb. n.are proposed:Jenopappiusniger(de Saeger, 1944),Jenopappiusaethiopica(de Saeger, 1944),Ypsilonigasterbumbana(de Saeger, 1942), andYpsilonigasterpteroloba(de Saeger, 1944).
