Hybrid molecules consisting of geraniol and butenolide were designed and synthesized by the late-stage divergent strategy. In the synthetic route, ring-closing metathesis was utilized for the construction of a butenolide moiety. A biological evaluation of the eight synthetic hybrid compounds revealed that these molecules exhibit antifouling activity against the cypris larvae of the barnacle Balanus (Amphibalanus) amphitrite with EC50 values of 0.30-1.31 μg mL-1. These results show that hybridization of the geraniol and butenolide structural motifs resulted in the enhancement of the antifouling activity.