The Roman Catholic Diocese of Pasig is the diocese of the Latin Church of the Catholic Church in the Philippines that comprises the cities of Pasig and Taguig, and the municipality of Pateros, in Metro Manila, Philippines. It was established by Pope John Paul II on June 28, 2003, by virtue of the papal bull Dei Caritas. It was formally and canonically erected on August 21, 2003, with the installation of Francisco C. San Diego as its first bishop. The Immaculate Conception Cathedral-Parish, located in the central vicinity of Pasig, was made the cathedral or the seat of the diocese.