Puerto Rico Highway 100 (PR-100) is a secondary highway in southwestern Puerto Rico, located mostly in the municipality of Cabo Rojo. This highway extends from PR-2 in Hormigueros, Puerto Rico and ends at PR-301.
Beginning at its intersection with PR-2 in Hormigueros, the highway runs south for about 16 kilometers and is the main gateway to local tourist destinations such as Boquerón, Combate (via PR-301 and PR-3301) and Puerto Real. It also connects PR-2 to PR-102. It is divided between PR-2 and PR-308, then it has segments of three lanes (2 to go and 1 returning, and later backwards) and two lanes. It ends at PR-301.