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.

[3] Mark Koevermans defeated Franco Davín 5–7, 6–4, 6–1 Sergio Casal / Javier Sánchez defeated Tom Kempers / Richard Krajicek 6–4, 6–3