William George McCloskey (May 1854 – July 9, 1924) officially played two years of Major League Baseball, in 1875 for the Washington Nationals, debuting on May 25, and in 1884 for the Wilmington Quicksteps of the Union Association. He played 11 games for the Washington Nationals in 1875 at catcher, batting .175 (7-for-40) with one run and four RBI. He played nine games in the 1884 season, splitting time between the outfield and catcher. In 30 at bats, he had three hits for a .100 batting average.