Macrosiagon is a genus of wedge-shaped beetles in the family Ripiphoridae. There are more than 20 described species in Macrosiagon. Under the rules of the ICZN, the nomenclatural gender of the genus name is feminine, as it is based on the Greek word "siagon" (σῐᾱγών), for "jaw", which is feminine in gender (), despite recent publications erroneously treating the gender as neuter (e.g. Batelka, J. (2003) New synonyms and notes on the distribution of Macrosiagon bipartitum and Macrosiagon cyaniveste (Coleoptera: Ripiphoridae). Acta Societatis Zoologicae Bohemicae, 67: 59–63.)
