Palaeoctonus is a genus of archosaur (possibly phytosaur) known only from isolated teeth. The genus includes the species P. appalachianus, P. aulacodus, P. cyphodon, P. dumblianus, and P. orthodon. The name is derived from Greek (palaios meaning "ancient", -ktonos meaning "killer"). The genus is believed to have flourished during the Upper (Late) Triassic period.