The 1991 ATP Tour World Championships was the men's tennis season-ending tournament. The singles event was also known as the IBM ATP Tour World Championships and was played on indoor
carpet courts at the
Festhalle Frankfurt in Germany. The doubles event, also known as the Standard Bank ATP Tour World Doubles Final, was played on indoor hard courts in held in
Johannesburg, South Africa. Both competitions were held between 12 November and 17 November 1991. Sixth-seeded
Pete Sampras won the singles title and
John Fitzgerald with
Anders Järryd won the doubles title.[3][4]