The University of Pennsylvania is a private research university based in Philadelphia, Pennsylvania, in the United States. It counts 1740 as its founding date, a year formally adopted by the trustees in 1899, although the institution's intellectual beginnings are more often traced to a 1749 pamphlet in which Benjamin Franklin argued for an academy in Philadelphia. Teaching began at the affiliated academy in 1751, and a collegiate charter followed in 1755, with Franklin acting as founder and first head of the board of trustees. Penn is one of the nine colonial colleges founded before American independence, is nonsectarian, and belongs to the Ivy League.

The university is organized into twelve schools, four of which admit undergraduates: the College of Arts and Sciences, the School of Engineering and Applied Science, the Wharton School, and the School of Nursing. Its graduate and professional divisions include the Perelman School of Medicine, generally described as the first medical school in North America, and the Carey Law School, whose earliest professor, James Wilson, took part in drafting the United States Constitution. Enrollment stands at roughly 29,100 students, of whom about 11,500 are undergraduates and some 17,600 are pursuing graduate or professional degrees. Academic staff numbered close to 4,800 in the most recent institutional count available.

Research activity is extensive. The Carnegie Classification places Penn among doctoral universities with very high research activity, and the university reported 2.172 billion dollars in research expenditure for fiscal year 2024, the second-highest total among American institutions in the National Science Foundation's HERD survey. ENIAC, an early general-purpose electronic computer, was completed on the campus in 1946, and the endowment stood at 24.8 billion dollars as of 30 June 2025. The main campus lies in the University City district of West Philadelphia and centers on College Hall, with Houston Hall and Franklin Field among its landmarks. Athletic teams compete as the Penn Quakers in NCAA Division I.