Cystoseira pustulata is a species of brown alga in the genus Cystoseira.
Cystoseira pustulata occurs in the Mediterranean and Northeast Atlantic (Azores, Canary Islands). Records of Cystoseira humilis in the Mediterranean refer to this species.
Cystoseira pustulata has variously been treated as a variety or subspecies of Cystoseira compressa, or considered a synonym of C. humilis, but constitutes a distinct genetic entity not closely related to either.