The history, taxonomy and nomenclatural issues revolving around the genus Flabellamon Ng, 1996, are reviewed. The genus of late contained two species, F. kuehnelti (Pretzmann, 1963) and F. wanchaii Takeda, Sanpool & Intapan, 2019. In the process of this review, two new species of this genus were uncovered from historical materials that were previously misidentified, and described herein as, F. ngankee sp. nov. (from northwestern Thailand) and F. mulayit sp. nov. (from southeastern Myanmar). Flabellamon ngankee sp. nov. is most similar superficially to F. wanchaii but can be distinguished easily by morphological differences in carapace armature, external orbital tooth, male pleonal margins and male gonopod. Flabellamon mulayit sp. nov. on the other hand, is more similar morphologically to F. kuehnelti, but can also be distinguished easily by epibranchial tooth and male gonopod characters. An identification key to the species of Flabellamon is provided.