Historical records state that Santo Tomas was created in 1764 through Spanish authorities who named the town Santo Tomas in honor of their patron saint, Santo Tomas de Aquinas. The town was formerly a part of Pangasinan before it became independent in 1764.
The first appointed governadorcillo was Don Lorenzo de los Reyes, a prominent native of the place. The Spanish authorities were displeased by his administration so Santo Tomas was merged with Agoo, a neighboring town. After almost a year of merging, the dynamic leadership of Don Domingo Carpio gave the town a hope for independence. He was a native of this town who courageously initiated the succession movement of Santo Tomas from Agoo. His sincerity and dedication won the overwhelming support of his town mates that forced the Spanish authorities to surrender the town in 1785 regaining its independence.
Under the administration of Don Domingo Carpio, Santo Tomas marked its marvelous growth and existence as independent municipality. Don Carpio was appointed governadorcillo because of his excellent performance. Due to his good example as a leader, he became an inspiration to his long line of native successors.
In 1843, the title governadorcillo given to a head of a town by Spanish authorities was changed to “Capitan”. Don Antonio Bernal was appointed the first Capitan in 1844, thereafter, deserving capitanes were appointed to the position until 1899 when the Spanish colonization came to an end. The last Capitan was Don Sixto Zandueta.
The American regime began to rule over the country in 1899. The local administration under American authorities asserted the designation of Municipal Presidente in place for the Capitanes. Don Bruno Pacho was the first “Presidente Municipal” of Santo Tomas and served up to 1901. Several successors were appointed and the last was Don Eusebio Tabora.
World War II broke out in 1941. The Japanese soldiers landed along the shores of Santo Tomas three days before Christmas. This temporarily relieved the town from American rule.
The Japanese authorities served their operation by organizing the municipal government. Municipal Mayor was appointed in 1942. Four municipal mayors served during the Japanese occupation. The term of Venancio Paculan ended shortly on January 15, 1945 after the Americans landed along the Lingayen Gulf to start the liberation of Luzon.
When the Commonwealth Government of the Philippines was formed, President Sergio Osmenia recognized its various units. Don Eusebio Tabora was reappointed as the first post liberation municipal mayor of Santo Tomas from January 19, 1945 to 1946.
On July 4, 1946, the Philippine Independence was restored by the Congress of the United States of America. President Manuel Roxas appointed Don Pedro Zarate to be the Municipal Mayor and served until the end of the year.
Under the Republic of the Philippines, local elections were held. The first elected mayor of Santo Tomas was Don Dominador Villanueva y Estacio. He was reelected as municipal mayor for eight consecutive years from January 1, 1947 to December 31, 1955.
The following are the Municipal Mayors who served and presently serving the municipality: