The Colegio de San Juan de Letran, also referred to by its acronym CSJL, is a private Catholic coeducational basic and higher education institution owned and run by the friars of the Order of Preachers in Intramuros, Manila, Philippines. It was founded in 1620. Colegio de San Juan de Letran has the distinction of being the oldest college in the Philippines and the oldest secondary institution in Asia. The school has produced Philippine presidents, revolutionary heroes, poets, legislators, members of the clergy, jurists, and it is also one of the only Philippine schools that has produced several Catholic saints who lived and studied on its campus. The school's patron saint is St. John the Baptist. The campus contains two statues, representing the two foremost alumni in the fields of secular and religious service: former Philippine President Manuel L. Quezon and Vietnamese Saint Vicente Liem de la Paz.

The Order of Preachers, also known as the Dominican Order, is a Catholic mendicant order of pontifical right that was founded in France by a Castilian priest named Dominic de Guzmán. It was approved by Pope Honorius III via the papal bull Religiosam vitam on 22 December 1216. Members of the order, who are referred to as Dominicans, generally display the letters OP after their names, standing for Ordinis Praedicatorum, meaning 'of the Order of Preachers'. Membership in the order includes friars, nuns, active sisters, and lay or secular Dominicans. More recently, there has been a growing number of associates of the religious sisters who are unrelated to the tertiaries.