Cladocyclus (derived from the Greek κλάδος/kládos ("branch") and κύκλος/kýklos ("circle")[1]) is an extinct genus of marine ichthyodectiform ray-finned fish from the middle Cretaceous.

It contains the following species: An indeterminate specimen, previously assigned to Chirocentrites, is known from the Albian-aged Pietraroja Plattenkalk of Italy.

[6][7] The species C. lewesiensis Agassiz, 1887 from the Cenomanian of England and C. strehlensis Geinitz, 1868 from the Turonian of Germany, which were described based only on fossil scales, are considered nomen dubia and likely do not belong to this genus.

[3][8][9] The dubious species C. occidentalis Leidy, 1857 from the Coniacian-to-Campanian-aged Niobrara Formation of South Dakota, US is based on scales that likely belong to Ichthyodectes ctenodon.

[10] Although C. gardneri and other cladocyclids are generally thought of as marine fish, the Australian species C. geddesi was recovered from a freshwater formation, despite showing clear adaptations to the open ocean.