Acanthonemus (from , 'spine' and 'to distribute' or 'covered') is an extinct genus of prehistoric marine ray-finned fish that lived from the early Eocene. It contains a single species, A. subaureus (synonyms: A. bertrandi <small>Agassiz, 1834</small>, A. filamentosus <small>Agassiz, 1834</small>), known from the famous Monte Bolca site in Italy. It is the only genus in the extinct family Acanthonemidae.