William John "Bullfrog" Dietrich (March 29, 1910 – June 20, 1978) was an American professional baseball pitcher.
He played in Major League Baseball (MLB) from 1933 to 1948 for the Philadelphia Athletics, Washington Senators, and Chicago White Sox.
In 16 seasons, Dietrich posted a 108–128 career record.
He recorded a winning mark in just three seasons, yet was usually close to .500 every year.
His best year in terms of wins was 1944 when he went 16–17 for the White Sox.On June 1, 1937, while with the White Sox, Dietrich no-hit the St.