Belosaepia is an extinct genus of cuttlefish-like cephalopod known from the Eocene.
Species of the genus Belosaepia reached in length and across and had a large siphuncle that penetrated its oblique septa. The shell was endogastrically coiled. It had a small belemnite-like guard, which took the form of a short horn at the posterior end of the shell; usually, only a small portion of the shell closest to the guard is preserved. The chambers in the shell closely resemble those present in the cuttlebone of modern cuttlefish.
Species of the genus Belosaepia lived close to the sea floor.