James John Hannan (January 7, 1940 in Jersey City, New Jersey) is an American retired professional baseball player who pitched in Major League Baseball from 1962 to 1971 for the Washington Senators, Detroit Tigers and Milwaukee Brewers. The right-hander stood 6 feet 3 inches (1.91 m) tall and weighed 205 pounds (93 kg). For his part, Hannan only got into seven games for the 1971 Tigers and was effective in middle relief, before being traded to the Brewers, where he finished his career with 21 appearances, 20 in relief, for Milwaukee.