S
- (Province of La Union) San Agustin East
- (Province of La Union) San Agustin Sur
- (Province of La Union) San Luis Sur
- (Province of Ilocos Sur) Sabang
- (Province of Ilocos Norte) Sagsagat
- (Province of Ilocos Sur) Sabangan
- (Province of Ilocos Sur) Sapriana
- (Province of Pangasinan) Sinkabayan
- (Province of Pangasinan) Santa Rosa
- (Province of Ilocos Sur) Sapaxa
- (Province of Ilocos Sur) San Juan
- (Province of Pangasinan) Songkoy
- (Province of Pangasinan) San Jose
- (Province of Pangasinan) San Jose
- (Province of Pangasinan) Sinabaan
- (Province of Pangasinan) San Cacoles
- (Province of Pangasinan) Sacat
- (Province of Pangasinan) Socony
- (Province of Pangasinan) Salomague Sur
- (Province of Pangasinan) Salomague
- (Province of Pangasinan) Santo Domingo
- (Province of Ilocos Norte) Santo Tomas
- (Province of Ilocos Norte) Sumiaat
- (Province of Ilocos Norte) San Antonio
- (Province of Ilocos Norte) Santa Maria
- (Province of Ilocos Norte) Sinuat
- (Province of Pangasinan) Silag
- (Province of Pangasinan) Simimbaan
- (Province of Ilocos Norte) Saoit
- (Province of Ilocos Norte) San Isidro