William Henry Dinneen, alternately spelled Dineen (April 5 1876 - January 13 1955), was an American right-handed pitcher in Major League Baseball who followed his 12-year career from 1898 to 1909 with a highly regarded tenure as an American League umpire from 1909 to 1937. Born in Syracuse, New York, he played for the Washington Senators and Boston Braves (both of the National League), and the Boston Red Sox and St. Louis Browns of the American League. Dinneen was most instrumental in helping the Red Sox win the first World Series in 1903, by winning three of Boston's five victories against the Pittsburgh Pirates. Dinneen also broke the record for most strikeouts in a World Series with 11; the previous mark of 10 had been set one day earlier by Pittsburgh's Deacon Phillippe.