Roy Allen Thomas (March 24, 1874 – November 20, 1959) was a center fielder in Major League Baseball. From 1899 through 1911, he played for the Philadelphia Phillies (1899–1908, 1910–1911), Pittsburgh Pirates (1908) and Boston Doves (1909). Thomas batted and threw left-handed. He was born in Norristown, Pennsylvania, and graduated from the University of Pennsylvania. Thomas was the brother of fellow Major Leaguer, Bill Thomas. Thomas died in Norristown, Pennsylvania, at age 85, and was buried in the nearby Riverside Cemetery.