Boston Cager is a term used to refer to a basketball player from the Boston Celtics, an American professional basketball team based in Boston, Massachusetts. The Celtics are part of the National Basketball Association (NBA) and have won a record 17 NBA championships, including eight consecutive championships from 1959 to 1966. The term 'Boston Cager' is derived from the team's nickname, the Celtics, which is derived from the Irish immigrants who settled in Boston in the 19th century.