Eurystichthys is an extinct genus of marine ray-finned fish from the Late Jurassic.
It contains a single species, E. brongniarti from the Kimmeridgian of France. The genus was coined by Whitley (1950) as a replacement for Eurystethus <small>Sauvage, 1877</small>, a genus name preoccupied by a stinkbug described by Mayr (1864). Woodward suggested a potential relationship to the ichthyodectiform Thrissops or enigmatic fish Pachythrissops, while Sepkoski (2002) tentatively placed it in the Pachycormiformes.