In the town of Sarrat, Ilocos Norte, the Sta. Monica Church stands as one of the most notable landmarks in the province. Known as the largest church in Ilocos Norte, it is especially recognized for the remarkable length of its nave. Built of red bricks in a mix of Earthquake Baroque and Neoclassical architecture, the church complex also includes a convent, a belfry, and a unique brick bridge staircase called the curillo, which connects the church and convent.

Sarrat was once a visita of Laoag and was originally named San Miguel to mark the arrival of the first Augustinian missionaries on September 29, 1724, the feast of Saint Michael the Archangel. The parish of Sta. Monica de Sarrat was established in the same year. Construction of the convent began in 1769 as a temporary chapel, and by 1779, the church, convent, belfry, and curillo were completed.

The church has endured multiple disasters over the centuries, including fires and earthquakes. Significant reconstructions took place in 1817, 1848, and the late 19th century. It was reinforced in the 1950s, and restoration efforts were supported by First Lady Imelda Marcos in 1977. After the widely publicized wedding of Irene Marcos and Gregorio Araneta in June 1983, the church suffered major damage from an earthquake two months later. Another earthquake in December 2024 caused further damage, prompting repairs.

Sta. Monica Church was declared an Important Cultural Property by the National Museum of the Philippines on September 27, 2009.