The Radical Party of Chile was a liberal political party that existed in Chile from 27 December 1863 to 18 August 1994. The party was founded on a radical and anti-Catholic clericalism platform, forming as the result of a split within the Liberal Party of Chile. The Radicals pushed through the theological reforms of the 1880s and ensured that marriage was no longer controlled by the Catholic Church. However, the Radicals adopted a moderate stance during the 20th century, shifting to the right under Gabriel Gonzalez Videla and oppressing Communist Party of Chile members. At the end of the 1960s, the leftists regained control of the Radical Party, and the party allied with the Socialist Party of Chile during the 1970 election. In 1971, the party officially stated that it had become a socialist party, and it was banned after the 1973 Chilean coup d'etat. The party supported Patricio Aylwin during his 1989 presidential campaign, which came after the restoration of democracy to Chile. In 1994, it merged into the Social Democrat Radical Party.
The Radical Party historically attracted the working class, artisans, and disenfranchised groups who sought social reforms and greater political representation. They were strong primarily in urban centers, with significant support in Santiago, reflecting the aspirations of those affected by social inequality.