Estoril Open (tennis)

The Estoril Open (also known as the Millennium Estoril Open for sponsorship purposes) is an ATP clay court tennis tournament held in the Portuguese Riviera. The event takes place at the sports complex of Clube de Ténis do Estoril in Cascais. The tournament was removed from the 2025 ATP calendar, and its future is uncertain.

Estoril Open was created by former Dutch tennis player Benno van Veggel and Portuguese football agent Jorge Mendes in 2015 to replace the Portugal Open, which was canceled due to lack of sponsorships.