Caeus is an extinct genus of prehistoric marine ray-finned fish, closely related to the modern milkfish. It contains a single species, C. leopoldi from the Early Cretaceous of the Pietraroja Plattenkalk, Italy.[2] It is one of the largest teleosts known from the Pietraroja formation, and is known by only a single specimen.[3]
It was first described as a genus without a species in 1857, before being officially described as a proper species in 1860. Some authorities have placed it as a species of the modern genus Chanos, but further studies have affirmed it as being a distinct genus. It is thought to be phylogenetically intermediate between Parachanos and Dastilbe.[3][4][5]