The 1990 IBM ATP Tour was the first season of the ATP Tour, the newly formed single world tennis circuit which came in replacing the two dual tours the ITF Grand Prix Circuit and WCT Circuit.

In 1990 the IBM ATP Tour included the four Grand Slam tournaments (organized by the International Tennis Federation (ITF)), the ATP Tour World Championships, the ATP Championship Series, Single-Week, the ATP Championship Series and the ATP World Series.

[1] The World Team Cup, Davis Cup (organized by the ITF) and Grand Slam Cup (organized by the ITF) are included in this calendar but did not count towards the Tour.

This is the complete schedule of events on the 1990 IBM ATP Tour, with player progression documented from the quarterfinals stage.

List of players and titles won, alphabetically by last name: The following players won their first title: