Frank Duncan was a professional baseball player who played as a pitcher for various teams during his career. He was born on September 20, 1902, in Kansas City, Missouri, and began his baseball career in the minor leagues in 1923. He played for several minor league teams before making his major league debut in 1927 with the Philadelphia Athletics.

Duncan played for the Athletics for two seasons before being traded to the St. Louis Browns in 1929. He played for the Browns for four seasons before being traded to the Detroit Tigers in 1933. He played for the Tigers for two seasons before being traded to the Boston Red Sox in 1935.

Duncan played for the Red Sox for two seasons before being traded to the Cleveland Indians in 1937. He played for the Indians for two seasons before being traded back to the Red Sox in 1939. He played for the Red Sox for one season before being traded to the Pittsburgh Pirates in 1940.

Duncan played for the Pirates for two seasons before being traded to the Brooklyn Dodgers in 1942. He played for the Dodgers for one season before being traded to the New York Giants in 1943. He played for the Giants for one season before being traded back to the Dodgers in 1944.

Duncan played for the Dodgers for two seasons before being traded to the Chicago Cubs in 1946. He played for the Cubs for one season before retiring from baseball in 1947.

Throughout his career, Duncan had a record of 119 wins and 115 losses with an ERA of 3.17. He was known for his control and his ability to pitch deep into games. He was also known for his durability, as he pitched over 200 innings in a season six times during his career.

After retiring from baseball, Duncan worked as a scout for the Pittsburgh Pirates. He died on December 20, 1988, at the age of 86.