1990 ATP Tour World Championships – Singles

Andre Agassi defeated the defending champion Stefan Edberg in the final, 5–7, 7–6(7–5), 7–5, 6–2 to win the singles title at the 1990 ATP Tour World Championships.

Arthur Ashe group
''Standings are determined by: 1. number of wins; 2. number of matches; 3. in two-players-ties, head-to-head records; 4. in three-players-ties, percentage of sets won, or of games won; 5. steering-committee decision.''

Cliff Drysdale group
''Standings are determined by: 1. number of wins; 2. number of matches; 3. in two-players-ties, head-to-head records; 4. in three-players-ties, percentage of sets won, or of games won; 5. steering-committee decision.''