The Boston Red Sox are an American professional baseball team based in Boston, Massachusetts. They compete in Major League Baseball (MLB) as a member club of the American League East division. The team have won nine World Series championships, tied for the third-most of any MLB team, and they have played in 14. Their most recent World Series appearance and win was in 2018. In addition, they won the 1904 American League pennant, but were not able to defend their 1903 World Series championship when the New York Giants refused to participate in the 1904 World Series.