S
- (Province of Isabela) San Juan
- (Province of Quirino) San Bernabe
- (Province of Isabela) San Mariano Norte
- (Province of Isabela) San Francisco Norte
- (Province of Isabela) San Isidro
- (Province of Isabela) San Vicente
- (Province of Isabela) Sinalugan
- (Province of Isabela) Santo Domingo
- (Province of Isabela) Sirigpit
- (Province of Isabela) San Mariano Sur
- (Province of Isabela) San Francisco Sur
- (Province of Isabela) Santa Isabel
- (Province of Isabela) Sinalugan
- (Province of Isabela) Salay
- (Province of Isabela) Santa Cruz
- (Province of Isabela) Salvacion
- (Province of Isabela) San Carlos
- (Province of Isabela) Santa Maria
- (Province of Isabela) Santa Ana
- (Province of Isabela) San Sebastian
- (Province of Isabela) San Isidro
- (Province of Isabela) Saguday Quirino
- (Province of Isabela) San Vicente
- (Province of Isabela) San Jose
- (Province of Isabela) San Antonio
- (Province of Quirino) San Marcos
- (Province of Isabela) San Roque
- (Province of Isabela) Salinungan West
- (Province of Isabela) Salinungan East
- (Province of Isabela) San Manuel