2021 Porto Open

The 2021 Porto Open was a professional tennis tournament played on hard courts. It was the first edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Porto, Portugal between 28 June and 4 July 2021.

Seeds

 * 1 Rankings are as of 21 June 2021.

Other entrants
The following players received wildcards into the singles main draw:
 * Nuno Borges
 * Gastão Elias
 * Gonçalo Oliveira

The following players received entry into the singles main draw as alternates:
 * 🇪🇸 Nicola Kuhn
 * 🇨🇦 Peter Polansky
 * 🇮🇹 Matteo Viola

The following players received entry from the qualifying draw:
 * 🇫🇷 Geoffrey Blancaneaux
 * 🇺🇸 Ulises Blanch
 * Sem Verbeek
 * 🇯🇵 Yosuke Watanuki

The following player received entry as a lucky loser:
 * Luís Faria

Singles

 * 🇹🇷 Altuğ Çelikbilek def. 🇫🇷 Quentin Halys 6–2, 6–1.

Doubles

 * 🇦🇷 Guido Andreozzi / 🇦🇷 Guillermo Durán def. 🇦🇷 Renzo Olivo / 🇲🇽 Miguel Ángel Reyes-Varela 6–7(5–7), 7–6(7–5), [11–9].