The Cathedral of Learning is a 42-story skyscraper that serves as the centerpiece of the University of Pittsburgh's (Pitt) main campus in the Oakland neighborhood of Pittsburgh, Pennsylvania. Standing at 535 feet (163 m), the 42-story Late Gothic Revival Cathedral is the tallest educational building in the Western Hemisphere and the second-tallest university building (fifth-tallest educationally-purposed building) in the world, after the main building of Moscow State University. It is also the second-tallest gothic-styled building in the world, after the Woolworth Building in Manhattan. The Cathedral of Learning was commissioned in 1921 and ground was broken in 1926 under general contractor Stone & Webster. The first class was held in the building in 1931 and its exterior finished in October 1934, prior to its formal dedication in June 1937. It is a Pittsburgh landmark listed in the National Register of Historic Places.

Colloquially referred to as "Cathy" by Pitt students, the Cathedral of Learning is a steel frame structure overlaid with Indiana limestone and contains more than 2,000 rooms and windows. It functions as a primary classroom and administrative center of the university, and is home to the Dietrich School of Arts and Sciences, the School of Social Work, and many of its departments, as well as the University Honors College. It houses many specialty spaces, including a studio theater, food court, study lounges, offices, computer and language labs, 31 Nationality Rooms, and a half-acre (2000 m², 22,000 ft²), 4-story-high, vaulted, gothic study and event hall. The building contains noted examples of stained glass, stone, wood, and iron work and is often used by the university in photographs, postcards, and other advertisements.