O'Neill, Tip (Thomas Philip O'Neill, Jr.), 1912–94, American political leader, Speaker of the U.S. House of Representatives (1977–87), b. Cambridge, Mass. A Democrat and unwavering New Deal liberal, he sat in the Massachusetts legislature from 1937, becoming its speaker in 1949. He entered the U.S. House of Representatives in 1953, filling the seat previously held by John F. Kennedy, and was an early opponent of the Vietnam War. A skillful strategist, he became majority whip in 1971 and majority leader in 1973 and was speaker of the House from 1977 to 1987. O'Neill was instrumental in bringing about the resignation of President Richard Nixon following investigations into the Watergate affair, and he instituted many reforms within the House of Representatives.
See his autobiography, Man of the House (1987); J. A. Farrell, Tip O'Neill and the Democratic Century (2001).