The Pichilemu area was long populated by the indigenous Promaucaes. European-Chilean development began in the mid-sixteenth century, as conquistadorPedro de Valdivia gave Juan Gómez de Almagro the Topocalma encomienda (which included the current territory of Pichilemu) in January 1541. Pichilemu was established as a subdelegation on 16 August 1867, and later as an "autonomous commune" on 22 December 1891, by decree of the President Jorge Montt and Interior Minister Manuel José Irarrázabal. Agustín Ross Edwards, a Chilean politician and member of the Ross Edwards family, planned to develop it as a beach resort on the Pacific Ocean for upper-class Chileans.
It remained in operation until the 1990s, and became a National Monument on September 16, 1994. It has since become an arts and culture center, and tourism information office. It exhibits decorative and practical objects from the 1920s, and features many old suits.