José Joaquín Pérez Mascayano (; 6 May 1801 – 1 July 1889) was a Chilean lawyer, diplomat, and politician who served as President of Chile from 1861 to 1871.
Born in Santiago to an aristocratic family, Pérez studied humanities at the Real Colegio Carolino and the Instituto Nacional before earning a law degree from the Royal University of San Felipe. His early career focused on diplomacy, serving as secretary of the Chilean legation in Washington, D.C. in 1826, chargé d'affaires in France in 1829, and representative to Buenos Aires in 1830.
As president, Pérez's administration promoted reconciliation and reform. He enacted an amnesty law for political disputes from 1851 to 1861, allowed greater freedom of the press, and passed the Law of Freedom of Worship in 1865.