1990 Norstar Bank Hamlet Challenge Cup
| 1990 Norstar Bank Hamlet Challenge Cup | |
|---|---|
| Date | August 20 – August 26 |
| Edition | 10th |
| Champions | |
| Singles | |
 Stefan Edberg | |
| Doubles | |
 Guy Forget /  Jakob Hlasek | |
The 1990 Norstar Bank Hamlet Challenge Cup was a tennis tournament played on outdoor hard courts. It was the 10th edition of the event (the first as a professional tournament and not an exhibition) known that year as the Norstar Bank Hamlet Challenge Cup, and was part of the ATP World Series of the 1990 ATP Tour. It took place at the Hamlet Golf and Country Club in Commack, Long Island, New York, United States, from August 20 to August 26, 1990.
The singles field was headlined by new World No. 1, Australian Open runner-up, Wimbledon champion, Indian Wells and Cincinnati titlist Stefan Edberg, French Open champion, Barcelona and Madrid winner Andrés Gómez, and Rotterdam and Orlando titlist Brad Gilbert. Other seeded players were Philadelphia and Manchester winner Pete Sampras, Stuttgart titlist Goran Ivanišević, John McEnroe, Jonas Svensson and Guy Forget.
Champions
Singles
Stefan Edberg def. 
Goran Ivanišević, 7–6, 6–3
- It was Stefan Edberg's sixth title of the year, and his 27th overall.
Doubles
Guy Forget / Jakob Hlasek def. 
Udo Riglewski / Michael Stich, 2–6, 6–3, 6–4