A new genus of Pteromalidae Neomegadicylus gen. nov., along with its type species Neomegadicylus gracileus sp. nov., is described from the Republic of Korea and Japan, and N. klarissae sp. nov., is described from the Republic of Korea. This genus can be distinguished from its putatively close relative Megadicylus Girault, 1929 by the following combination of characters-antennal clava with large micropilosity area, F1-F6 much longer than broad; clypeus smooth and shiny; notauli deep and incomplete and anterior part of propodeum strongly sloping in lateral view. An identification key to species of Neomegadicylus is provided, based on females.