Robert Gustave "Bun" Troy (27 August 1888 – 7 October 1918) was a German-born Major League Baseball pitcher who was killed in action while serving with the U.S. Army during World War I at Petit Majouym, France. Born in Wurzach, Germany, Troy was a right-handed pitcher who played in a single major league baseball game on September 15, 1912. He started the game for the Detroit Tigers, pitched 6.2 innings, giving up 4 runs. He gave up 9 hits, 3 walks, and hit one batter with a pitch. Troy later pitched for the Pittsfield Electrics.