As manager William Mitchell Nash (June 24, 1865 – November 15, 1929) was an American Major League Baseball third baseman.

Nash entered the professional leagues with his hometown team the Richmond Virginians of the American Association in 1884 as a nineteen-year-old.

He became a minor league manager in Buffalo and Hartford after his playing days ended.

He ran a variety of jobs after finishing baseball, such as managing a hotel in Buffalo, umpiring for a time in 1901 and studying for a MD to serve in the medical department in Wrentham, Massachusetts.

While inspecting a medical facility in East Orange, New Jersey, he had a fatal heart attack at 64 on November 15, 1929.