Orthaspidoceras is an extinct ammonoid cephalopod genus belonging to the family Aspidoceratidae.

These nektonic carnivores lived during the Jurassic period, Kimmeridgian age.

[2] Shells of Orthaspidoceras are medium or large-sized, with a diameter reaching about 20–25 centimetres (7.9–9.8 in).

These shells are relatively involute and thick, with a quadrate-rounded or depressed whorls.

The ornamentation consists of a row of coarse tubercles and fine streaks.