''Penicillus'' may refer to:
*
''Penicillus'' (alga), a green alga genus in the family Udoteaceae
*
''Penicillus'' (bivalve), a mollusc genus in the family
Clavagellidae
Clavagellidae is a family of very unusual marine bivalves of the order Anomalodesmata.
Genera and species
* †'' Ascaulocardium'' Pojeta and N. F 1987
* '' Brechites'' Guettard 1770
** '' Brechites attrahens''
** '' Brechites brechites''
** ' ...
{{genus disambiguation