Actinopteri (/æktɪˈnɒptəraɪ/) is the sister group of Cladistia (bichirs) in the class Actinopterygii (ray-finned fish).

Dating back to the Permian period, the Actinopteri comprise the Chondrostei (sturgeons and paddlefish), the Holostei (bowfins and gars), and the teleosts; in other words, all extant ray-finned fish other than the bichirs.

[1] Characters of Actinopteri include [2] paired fin structure, a single dorsal fin, fulcra, a large median gular and numerous branchiostegals, ganoid scales, and a valvula cerebelli in the brain.

The following cladogram[3][4][5][6] summarizes the evolutionary relationships of extant Actinopteri.

Divergence time for each clade in mya are based on:[7] Acipenseriformes (sturgeons, paddlefish) Teleostei 310 mya Amiiformes (bowfin) Lepisosteiformes (gars, alligator gars)