| 1990 Athens Open | |
|---|---|
| Date | 1–7 October |
| Edition | 5th |
| Category | World Series |
| Draw | 32S / 16D |
| Prize money | $125,000 |
| Surface | Clay / outdoor |
| Location | Athens, Greece |
| Champions | |
| Singles | |
 Mark Koevermans | |
| Doubles | |
 Sergio Casal / Javier Sánchez | |
The 1990 ATP Athens Open was a men's tennis tournament played on outdoor clay courts in Athens in Greece that was part of the World Series of the 1990 ATP Tour. It was held from 1 October through 7 October 1990. Seventh-seeded Mark Koevermans won the singles title.
