James Joseph `` Jim '' Parsons ( born March 24 , 1973 in Houston , Texas ) is an American actor . Parsons is best known for playing the role of Sheldon Cooper in the television show , The Big Bang Theory . James Joseph `` Jim '' Parsons ( born March 24 , 1973 ) is an American television and film actor best known for playing Sheldon Cooper on the CBS sitcom The Big Bang Theory , with his performance often cited as a significant reason for the program 's success .