Ianthodon is an extinct genus of basal haptodontiform synapsids from the Late Carboniferous about 304 million years ago. The taxon was discovered and named by Kissel & Reisz in 2004. The only species in the taxon, Ianthodon schultzei, was found by separating it from a block that also contained the remains of Petrolacosaurus and was initially thought to contain elements of Haptodus. The evolutionary significance of the taxon was not realized until a publication in 2015. The fossil of this organism was discovered in Garnett, Kansas.