Three new genera and species of Mymaridae from the Neotropical region are described: Megamymar waorani Huber, gen. and sp. nov.; Neopolynemoidea chilensis Huber, gen. and sp. nov.; and Porcepicus herison Huber, gen. and sp. nov. Their possible relationships are discussed to place them in context among the previously described genera of Mymaridae.