Massachusetts's 9th congressional district special election of 2001 was held in the U.S. state on October 16, 2001, to fill the vacancy caused by the death of Representative Joe Moakley. Democratic state senator Stephen F. Lynch won the election over Republican state senator Jo Ann Sprague.
Primary elections were held on September 11, 2001. The election was overshadowed by the September 11 attacks, which occurred shortly after polls opened.
Incumbent U.S. representative Joe Moakley, who was first elected in 1972, died on May 28, 2001. Primary elections to nominate candidates were scheduled for September 11, and a special election to fill the vacancy was scheduled for October 16.