2021 Estoril Open

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.

Singles

 * 🇪🇸 Albert Ramos Viñolas def. 🇬🇧 Cameron Norrie, 4–6, 6–3, 7–6(7–3).

Doubles

 * Hugo Nys / 🇩🇪 Tim Pütz def. 🇬🇧 Luke Bambridge / 🇬🇧 Dominic Inglot, 7–5, 3–6, [10–3].

Prize money

 * per team

Seeds

 * 1 Rankings are as of 19 April 2021

Other entrants
The following players received wildcards into the main draw:
 * 🇯🇵 Kei Nishikori
 * 🇨🇦 Denis Shapovalov
 * João Sousa

The following players received entry from the qualifying draw:
 * 🇪🇸 Carlos Alcaraz
 * Nuno Borges
 * 🇪🇸 Pedro Martínez
 * 🇪🇸 Jaume Munar

The following player received entry as a lucky loser:
 * 🇪🇸 Roberto Carballés Baena

Withdrawals

 * Before the tournament
 * 🇪🇸 Pablo Carreño Busta → replaced by Kevin Anderson
 * 🇮🇹 Fabio Fognini → replaced by 🇫🇷 Pierre-Hugues Herbert
 * 🇫🇷 Gaël Monfils → replaced by 🇮🇹 Marco Cecchinato
 * 🇯🇵 Kei Nishikori → replaced by 🇪🇸 Roberto Carballés Baena
 * 🇫🇷 Benoît Paire → replaced by 🇪🇸 Fernando Verdasco
 * 🇦🇷 Diego Schwartzman → replaced by 🇦🇷 Juan Ignacio Londero


 * During the tournament
 * 🇫🇷 Richard Gasquet

Retirements

 * Kevin Anderson

Seeds

 * Rankings are as of 19 April 2021

Other entrants
The following pairs received wildcards into the doubles main draw:
 * Frederico Ferreira Silva / Pedro Sousa
 * 🇬🇧 Cameron Norrie / João Sousa

Withdrawals

 * Before the tournament
 * Romain Arneodo / 🇫🇷 Benoît Paire → replaced by 🇺🇸 Nicholas Monroe / 🇺🇸 Frances Tiafoe
 * 🇪🇸 Marcel Granollers / 🇦🇷 Horacio Zeballos → replaced by Cristian Garín / 🇪🇸 David Vega Hernández