Sphenocephalus (from Greek: σφήν sphḗn, 'wedge' and Greek: κεφαλή kephalḗ 'head') is an extinct genus of ray-finned fish that lived during the Cretaceous period.

Sphenocephalus was about 20 centimetres (8 in) long, with a rather large head, and may have resembled a modern black bass in appearance.

It was one of the earliest fish to have the pelvic fins placed beneath th pectoral fins, a common feature in modern fish that improves swimming manoeuvrability.

Like the modern trout-perches, it possessed a mixture of modern and primitive features, and it was probably one of the earliest perciform fish.

This article about a prehistoric ray-finned fish is a stub.