2021 Miami Open – Men's singles

Hubert Hurkacz defeated Jannik Sinner in the final, 7–6(7–4), 6–4 to win the men's singles tennis title at the 2021 Miami Open. It was his first Masters 1000 singles title, and he became the first Pole to win a Masters 1000 singles title.

Roger Federer was the reigning champion from when the tournament was last held in 2019, but chose not to participate this year.

As both Novak Djokovic and Rafael Nadal also chose not to participate, this was the first Masters 1000 tournament since the 2004 Paris Masters without at least one member of the Big Three competing.

Seeds
All seeds received a bye into the second round. • 🇷🇺 Daniil Medvedev (quarterfinals)

• Stefanos Tsitsipas (quarterfinals)

• 🇩🇪 Alexander Zverev (second round)

• 🇷🇺 Andrey Rublev (semifinals)

• 🇦🇷 Diego Schwartzman (fourth round)

• 🇨🇦 Denis Shapovalov (third round)

• 🇪🇸 Roberto Bautista Agut (semifinals)

• 🇧🇪 David Goffin (second round)

• 🇧🇬 Grigor Dimitrov (second round)

• 🇮🇹 Fabio Fognini (second round)

• 🇨🇦 Félix Auger-Aliassime (third round)

• 🇨🇦 Milos Raonic (fourth round)

•  Cristian Garín (second round)

• 🇷🇺 Karen Khachanov (third round)

• 🇦🇺 Alex de Minaur (second round)

• 🇷🇸 Dušan Lajović (third round)

• 🇷🇺 Aslan Karatsev (third round)

• 🇺🇸 John Isner (fourth round)

• 🇬🇧 Dan Evans (second round)

• 🇫🇷 Ugo Humbert (third round)

• 🇮🇹 Jannik Sinner (final)

• 🇺🇸 Taylor Fritz (fourth round)

• 🇫🇷 Benoît Paire (second round)

• 🇮🇹 Lorenzo Sonego (fourth round)

• 🇫🇷 Adrian Mannarino (third round)

• 🇵🇱 Hubert Hurkacz (champion)

•  Nikoloz Basilashvili (second round)

• 🇯🇵 Kei Nishikori (third round)

• 🇭🇺 Márton Fucsovics (third round)

• 🇺🇸 Reilly Opelka (second round)

• 🇩🇪 Jan-Lennard Struff (third round)

• 🇰🇿 Alexander Bublik (quarterfinals)

Seeds
• # 🇺🇸 Mackenzie McDonald (qualified)

• # 🇧🇷 Thiago Seyboth Wild (qualified)

• # 🇧🇦 Damir Džumhur (qualifying competition, lucky loser)

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

• # Henri Laaksonen (first round)

• # 🇮🇹 Federico Gaio (qualifying competition, lucky loser)

• # 🇩🇪 Daniel Altmaier (first round, retired)

• # 🇯🇵 Go Soeda (first round)

• # 🇺🇸 Brandon Nakashima (qualifying competition)

• # Jason Jung (qualifying competition)

• # 🇪🇸 Bernabé Zapata Miralles (first round)

• # Marc-Andrea Hüsler (qualifying competition)

• # 🇺🇸 Maxime Cressy (first round)

• # 🇮🇹 Paolo Lorenzi (qualified)

• # 🇬🇧 Liam Broady (qualified)

• # 🇷🇸 Danilo Petrović (first round)

• # 🇮🇹 Lorenzo Giustino (first round)

• # Alejandro Tabilo (qualified)

• # Ivo Karlović (qualifying competition)

• # Frederico Ferreira Silva (first round)

• # 🇪🇨 Emilio Gómez (qualifying competition)

• # 🇮🇹 Thomas Fabbiano (qualified)

• # 🇰🇿 Dmitry Popko (first round)

• # Mikael Torpegaard (first round)

Qualifiers
• # 🇺🇸 Mackenzie McDonald

• # 🇧🇷 Thiago Seyboth Wild

• # Alejandro Tabilo

• # 🇦🇺 Thanasi Kokkinakis

• # 🇮🇹 Thomas Fabbiano

• # 🇬🇧 Liam Broady

• # 🇯🇵 Shintaro Mochizuki

• # 🇺🇸 Emilio Nava

• # 🇺🇸 Ernesto Escobedo

• # 🇮🇹 Paolo Lorenzi

• # 🇩🇪 Mischa Zverev

• # 🇺🇸 Bjorn Fratangelo

Lucky losers
• # 🇮🇹 Federico Gaio

• # 🇧🇦 Damir Džumhur