The University of Santo Tomas (also known as UST, and officially as Pontifical and Royal University of Santo Tomas, Manila) is a private, Catholic research university in Manila, Philippines. Founded on April 28, 1611, by Spanish friar Miguel de Benavides, third Archbishop of Manila, it has the oldest extant university charter in the Philippines and in Asia, and is one of the world's largest Catholic universities in terms of enrollment found on one campus. It is the main campus of the University of Santo Tomas System that is run by the Order of Preachers.UST was granted the title “Royal” by King Charles III of Spain in 1785. Pope Leo XIII made UST a "Pontifical" university in 1902. Pope Pius XII bestowed upon UST the title of “The Catholic University of the Philippines” in 1947. UST houses the first and oldest engineering, law, medical, and pharmacy schools in the country.

The main campus is the largest university in the city of Manila and is home to 22 degree-granting colleges, a parish church, and a teaching hospital. In 2011, four of the university's structures were declared National Cultural Treasures by the National Museum.

The university offers programs in over 180 undergraduate and graduate specializations. It has 26 programs recognized by the Commission on Higher Education (CHED) as Centers of Excellence and Centers of Development, ranking second in the country and first among private educational institutions. It is awarded with an institutional accreditation by the CHED through the Federation of Accrediting Agencies of the Philippines (FAAP). The university has the highest number of Philippine Association of Colleges and Universities' Commission on Accreditation (PACUCOA)-accredited programs in the country with 59.UST alumni and faculty include 11 catholic saints, 2 cardinals, 4 presidents of the Philippines, 9 chief justices, 19 national artists, a national scientist, and 5 billionaires. The athletic teams are the Growling Tigers, who are members of the University Athletic Association of the Philippines and have won 44 overall championships in 73 seasons.