William J. Reinhart (August 2, 1896 – February 14, 1971) was an American college basketball, football, and baseball coach at the George Washington University, the University of Oregon, and the United States Merchant Marine Academy. From 1923 to 1935, he served as the head basketball coach at Oregon. He is the school's second-winningest coach with 180 victories. His record through 13 seasons at Oregon was 180–101. He suffered only one losing season. Largely due to his success, Oregon was forced to build McArthur Court to accommodate the large crowds that became fixtures for Ducks games on his watch.