1990 ATP Championship Series, Single Week Singles Singles

| Tournament | Surface | Week | Winner_and_score | Finalist | Semifinalists |
|---|---|---|---|---|---|
| Toronto | Hard | July 23 | Michael Chang (7) * 4–6, 6–3, 7–6 | Jay Berger (4) | Pete Sampras (5) Jakob Hlasek |
| Cincinnati | Hard | August 6 | Stefan Edberg (1) 6–1, 6–1 | Brad Gilbert (4) | Andrés Gómez (3) Scott Davis |
| Stockholm | Carpet (i) | October 22 | Boris Becker (2) 6–4, 6–0, 6–3 | Stefan Edberg (1) | Alexander Volkov Pete Sampras (4) |
| Paris | Carpet (i) | October 29 | Stefan Edberg (1) 3–3 Ret. | Boris Becker (2) | Sergi Bruguera Jonas Svensson (14) |