Santo Tomás, officially the Municipality of Santo Tomas, is a coastal municipality in the province of La Union, Philippines. According to th…Santo Tomás, officially the Municipality of Santo Tomas, is a coastal municipality in the province of La Union, Philippines. According to the 2020 census, it has a population of 40,846 people. The name Santo Tomás originates from the Spanish term for Saint Thomas, a 13th-century Catholic priest, philosopher, and theologian celebrated for synthesizing faith and reason, authoring the Summa Theologica, and shaping Western Christian thought.