Guajataca is a barrio in the municipality of San Sebastián, Puerto Rico. Its population in 2010 was 603. The Guajataka Scout Reservation is located within Barrio Guajataka.

San Sebastián is a town and municipality of Puerto Rico located in the northwestern region of the island, south of Isabela, Quebradillas and Camuy; north of Las Marías; east of Moca and Añasco; and west of Lares. San Sebastián is spread over twenty-four barrios and San Sebastián Pueblo. It is a principal city of the Aguadilla-Isabela-San Sebastián Metropolitan Statistical Area.