John Spencer Sharp (born July 28, 1950) is an American Democratic politician from Texas, who has served since 2011 as the chancellor of the Texas A&M University System. From 1991 to 1999, he was the Texas Comptroller of Public Accounts. From 1979 to 1987, he was a member of both houses of the Texas State Legislature. From 1987 to 1991, he was one of the three members of the Texas Railroad Commission. In 1998 and 2002, he was the Democratic Party's nominee for Lieutenant Governor of Texas.