Ectoconus (Greek: "outside" (ektos), "cone" (konos)[1]) is an extinct genus of terrestrial herbivorous mammal of the family Periptychidae, endemic to North America during the Early Paleocene subepochs (66—63.3 mya) existing for approximately 2.7 million years.

[3] Ectoconus was stoutly built, sheep-sized condylarth and had a small braincase, short, strong limbs and a heavy tail.

Its feet had five hooved digits much in the manner of extremely primitive ungulates.

It was assigned to Periptychidae by Cope (1884), Cope (1888), Osborn and Earle (1895), Matthew (1937) and Carroll (1988); and to Periptychinae by Archibald (1998) and Eberle (2003).

This prehistoric mammal-related article is a stub.