Jaime L. Sin (born 1928) was a cardinal of the Roman Catholic Church who served in the Philippines. He was instrumental in the defeat of the Marcos regime and in the installation of Corazon Aquino as president in 1986.

Jaime L. Sin, cardinal of the Roman Catholic Church, was born in the town of New Washington, Aklan, in the Visayan Islands of the Philippines on August 21, 1928. He was the seventh of nine children of Juan Sin and Maxima Lachica.

Cardinal Sin began his missionary career in Jaro, Iloilo, where he attended the Jaro Archdiocesan Seminary of St. Vincent Ferrer. He was ordained a priest on April 3, 1954. He served as priest of the Diocese of Capiz from 1954 to 1957 and became rector of St. Pius X Seminary in Roxas City from 1957 to 1967. While serving in the church he obtained a bachelor's degree in education from the Immaculate Concepcion College in 1959. In 1960 Pope...