| 2021 Estoril Open | |
|---|---|
 | |
| Date | 26 April – 2 May |
| Edition | 6th |
| Category | ATP Tour 250 |
| Draw | 28S / 16D |
| Prize money | €481,270 |
| Surface | Clay / outdoor |
| Location | Cascais, Portugal |
| Venue | Clube de Ténis do Estoril |
| Champions | |
| Singles | |
 Albert Ramos Viñolas | |
| Doubles | |
 Hugo Nys /  Tim Pütz | |
The 2021 Estoril Open is a men's tennis tournament played on outdoor clay courts. It is the 6th edition of the tournament and part of the ATP Tour 250 series of the 2021 ATP Tour. It tames place at the Clube de Ténis do Estoril in Cascais, Portugal, from 26 April through 2 May 2021. Seventh-seeded Albert Ramos Viñolas won the singles title.[1]
- ^ "Millennium Estoril Open Overview". atptour.com.