Brachydegma is an extinct genus of prehistoric freshwater ray-finned fish that lived during the Leonardian age (Cisuralian/lower Permian) in what is now Texas, United States.

A potential record is also known from the concurrent Hennessey Formation of Oklahoma.

[3] It is one of the only fossil ray-finned fish from the Permian that preserves the skull bones in three dimensions.

[4] A later study rather suggested that Brachydegma could be one of the earliest crown neopterygians (Halecomorphi) known from the fossil record.

It appears to be closely related or possibly a member of the crown group of Actinopterygii, though a closer relationship with either Neopterygii or Polypteriformes appears plausible.