Jesse Joseph Haines (July 22, 1893 – August 5, 1978), nicknamed "Pop", was a right-handed pitcher in for the Cincinnati Reds and St. Louis Cardinals of Major League Baseball (MLB). After a lengthy stint in minor league baseball, he played briefly in 1918, then from 1920 to 1937. He spent nearly his entire major league career with the Cardinals. Haines pitched on three World Series championship teams. Though he had a kind personality off the field, Haines was known as a fiery competitor during games.

After retiring in 1937 with a 210–158 win–loss record, Haines was a coach with the Brooklyn Dodgers in 1938. He left baseball after that season and returned to his native Ohio. He was elected to the Baseball Hall of Fame in 1970. However, his election was not without controversy, as the Veterans Committee included former teammates of Haines, resulting in charges of cronyism against the Veterans Committee. In 2014, he was inducted into the St. Louis Cardinals Hall of Fame Museum. He ranks second in franchise history in shutouts.