Bradford, city, McKean county, northern Pennsylvania, U.S., on the forks of the Tunungwant (Tuna) River, near the New York state border. Settlers first came to the area about 1823 or 1827, but Bradford itself was not established until 1837. First called Littleton, it took the name Bradford after 1854, probably for the New Hampshire home of many of its settlers. The discovery of oil (1871) brought sudden wealth, and in 1881, the peak year of production, the area was producing some three-fourths of the world’s output. Production declined at the end of the 19th century but increased after 1906 when a water-flooding process was introduced.

Oil production has remained significant but has been overshadowed economically by diversified manufactures, including lighters, pipe couplings, semiconductors, cutlery, corrugated containers, and wood products. The Bradford campus of the University of Pittsburgh opened in 1963. The Penn-Brad Oil Museum, Allegheny National Forest, and the Cornplanter Indian Reservation (the state’s last Indian reserve) are nearby. Inc. city, 1879. Pop. (2000) 9,175; (2010) 8,770.