Clymeniida is an order of ammonoid cephalopods from the Upper Devonian characterized by having an unusual dorsal siphuncle.

Developmentally, the siphuncle in clymeniids starts off ventrally, like that in other ammonoids, but after the first few septa it migrates to a dorsal position indefinitely.

Septal necks are retrosiphonate, characteristic of their nautiloid ancestors, and are commonly very long, forming an almost continuous siphuncular tube.

The septa, unusually simplified in shape, are convex toward the front as is characteristic of ammonoids.

Miller, Furnish, and Schindewolf, 1957, in Part L of the Treatise on Invertebrate Paleontology[2] included three superfamilies in Clymeniida: Gonioclymeniaceae, Clymeniaceae, and Parawocklumeriaceae.