Santa Maria, officially the Municipality of Santa Maria, is a municipality in the province of Isabela, Philippines. According to the 2020 census, it …Santa Maria, officially the Municipality of Santa Maria, is a municipality in the province of Isabela, Philippines. According to the 2020 census, it has a population of 25,758 people. Santa Maria, a former barrio of San Pablo, is named after Doña Maria, the firstborn child of Don Pablo Marasigan, a Spaniard, and Doña Masid, a native.