William John Orr (April 22, 1891 – March 10, 1967) was a Major League Baseball infielder. He played parts of two seasons in the majors, 1913 and 1914, for the Philadelphia Athletics. He played primarily at shortstop, but also played all three other infield positions.
After his major league career, Orr played for ten years in the Pacific Coast League. He also briefly served as head coach of the Stanford Cardinal baseball program, and managed the Salt Lake City Bees in 1926.