Immaculate Conception Parish Church is the oldest Roman Catholic church Los Baños, Laguna, Philippines. Its titular is the Nuestra Señora de Agua Santa la Inmaculada Concepcion de Maynit,
The town of Los Baños started as a visita of Bay under the Augustinian order with St. Nicolas de Tolentino as titular. In 1590, Franciscans replaced the Augustinians in their missions with Fray Pedro Bautista, later canonized as San Pedro Bautista. He discovered numerous hot springs in the area which locals called Maynit. He created a public bath he called the “Los Baños" After twenty years, the Franciscans established a temporary convent to administer the hot springs that were popular for healing illnesses. A small hospital chapel was built in 1613 in the absence of a church until 1727.Under the supervision of gobernadorcillo Don Juan Castañeda, a church in honor of Nuestra Señora de Immaculada Concepcion was built in 1671.
