| Singles | |
|---|---|
| 1989 WCT Finals | |
| Champion |  John McEnroe |
| Runner-up | Brad Gilbert |
| Score | 6–3, 6–3, 7–6 |
Boris Becker was the defending champion but did not compete that year.
John McEnroe won in the final 6–3, 6–3, 7–6 against Brad Gilbert.
The finals were held in Dallas, Texas at Reunion Arena.
A champion seed is indicated in bold text while text in italics indicates the round in which that seed was eliminated.
John McEnroe (champion)
Mats Wilander (quarterfinals)
Ivan Lendl (semifinals) Stefan Edberg (quarterfinals)| Quarterfinals | Semifinals | Final | ||||||||||||||||||||||||
| 1 | John McEnroe | 4 | 3 | |||||||||||||||||||||||
| Andre Agassi | 6 | 0r | ||||||||||||||||||||||||
| 1 | John McEnroe | 6 | 7 | 6 | 7 | |||||||||||||||||||||
| 3 | Ivan Lendl | 7 | 6 | 2 | 5 | |||||||||||||||||||||
| 3 | Ivan Lendl | 7 | 1 | 7 | 6 | 7 | ||||||||||||||||||||
 Jakob Hlasek | 6 | 6 | 6 | 7 | 6 | |||||||||||||||||||||
| 1 | John McEnroe | 6 | 6 | 7 | ||||||||||||||||||||||
| Brad Gilbert | 3 | 3 | 6 | |||||||||||||||||||||||
| Brad Gilbert | 7 | 6 | 6 | |||||||||||||||||||||||
| 4 | Stefan Edberg | 6 | 1 | 3 | ||||||||||||||||||||||
| Brad Gilbert | 6 | 6 | 6 | 6 | ||||||||||||||||||||||
| Mikael Pernfors | 3 | 7 | 3 | 3 | ||||||||||||||||||||||
| Mikael Pernfors | 2 | 6 | 3 | 6 | 6 | |||||||||||||||||||||
| 2 | Mats Wilander | 6 | 1 | 6 | 2 | 3 | ||||||||||||||||||||
Michael Chang defeated Jay Berger in the final, 4–6, 6–3, 7–6(7–3) to win the men's singles tennis title at the 1990 Canadian Open. With the win, Chang became the youngest Masters champion in history.
Boris Becker won in the final 6–4, 6–3, 7–6 against Sergio Casal.
Amos Mansdorf was the defending champion but lost in the first round to Michael Chang.
Vitas Gerulaitis was the defending champion but lost in the semifinals to Björn Borg.
Ivan Lendl was the defending champion but lost in the final 6–2, 4–6, 6–3, 6–7, 7–6 to John McEnroe.
First-seeded John McEnroe was the defending champion and won in the final, which lasted 1h39, against Jimmy Connors in straight sets 6–1, 6–2, 6–3.
John McEnroe was the defending champion but lost in the quarterfinals to Joakim Nyström.
Anders Järryd was the defending champion but did not compete that year.
Joakim Nyström was the defending champion but did not compete that year.
John McEnroe was the defending champion but lost in the semifinals to Boris Becker.
Mark Kratzmann and Wally Masur were the defending champions but only Masur competed that year with Pat Cash.
Derrick Rostagno was the defending champion but lost in the semifinals to Goran Ivanišević.
Petr Korda was the defending champion but lost in the quarterfinals to Fabrice Santoro.
Petr Korda and Wally Masur were the defending champions but they competed with different partners that year, Korda with Jim Pugh and Masur with Mark Kratzmann.
Boris Becker was the defending champion but lost in the quarterfinals to Richard Krajicek.
Jonas Björkman and Nicklas Kulti won in the final 6–4, 6–4 against Yevgeny Kafelnikov and Menno Oosting.
Ken Flach and Robert Seguso were the defending champions but lost in the quarterfinals to Jeremy Bates and Kevin Curren.
Martina Navratilova and Emilio Sánchez were the defending champions but did not compete that year.
Jakob Hlasek and John McEnroe were the defending champions but this time Hlasek played in pair with Frenchman Guy Forget and lost in the second round to Australians Mark Woodforde and Todd Woodbridge.
The 1991 Grand Prix de Tennis de Toulouse was a men's tennis tournament played on indoor carpet courts in Toulouse, France that was part of the World Series of the 1991 ATP Tour. It was the tenth edition of the tournament and was held from 30 September until 6 October 1991.