The 1998 MFS Pro Tennis Championships, also known as the U.S.

Pro Tennis Championships, was a men's tennis tournament played on outdoor hard courts at the Longwood Cricket Club in Boston, United States that was part of the World Series of the 1998 ATP Tour.

It was the 70th edition of the tournament and was held from August 24 through August 30, 1998.

Michael Chang won the singles title.

Michael Chang defeated Paul Haarhuis, 6–3, 6–4 Jacco Eltingh / Paul Haarhuis defeated Chris Haggard / Jack Waite, 6–3, 6–2