2021 Abierto Mexicano Telcel – Singles

Alexander Zverev defeated top seed Stefanos Tsitsipas in the final, 6–4, 7–6(7–3) to win the men's singles tennis title at the 2021 Mexican Open.

Rafael Nadal was the defending champion, but chose not to defend his title.

Seeds
• # Stefanos Tsitsipas (final)

• #🇩🇪 Alexander Zverev (champion)

• #🇦🇷 Diego Schwartzman (first round)

• #🇨🇦 Milos Raonic (second round)

• #🇧🇬 Grigor Dimitrov (quarterfinals)

• #🇮🇹 Fabio Fognini (second round)

• #🇨🇦 Félix Auger-Aliassime (quarterfinals)

• #🇳🇴 Casper Ruud (quarterfinals, withdrew)

Seeds
• # 🇮🇹 Salvatore Caruso (moved to main draw)

• # João Sousa (second round)

• # 🇮🇹 Lorenzo Musetti (qualified)

• # 🇺🇸 Denis Kudla (qualifying competition, lucky loser)

• # 🇧🇷 Thiago Seyboth Wild (second round)

• # 🇧🇦 Damir Džumhur (second round, defaulted)

• # 🇩🇪 Cedrik-Marcel Stebe (second round)

• # Henri Laaksonen (first round)

Qualifiers
• # 🇺🇸 Brandon Nakashima

• # 🇺🇸 Stefan Kozlov

• # 🇮🇹 Lorenzo Musetti

• # Tallon Griekspoor

Lucky loser
• # 🇺🇸 Denis Kudla