2020 Western & Southern Open – Men's singles

Novak Djokovic defeated Milos Raonic in the final, 1–6, 6–3, 6–4 to win the men's singles tennis title at the 2020 Cincinnati Masters. With the win, he claimed his record-equaling 35th Masters 1000 title (tying Rafael Nadal's tally), and completed the double career Golden Masters. Djokovic became the first new singles titleist on the ATP Tour since its suspension due to the COVID-19 pandemic in March 2020.

Daniil Medvedev was the defending champion, but lost in the quarterfinals to Roberto Bautista Agut.

Due to the COVID-19 pandemic, this edition of the tournament was held at the USTA Billie Jean King National Tennis Center shortly before the 2020 US Open to minimize travel risks.

Seeds
The top eight seeds receive a bye into the second round. • 🇷🇸 Novak Djokovic (champion)

• 🇦🇹 Dominic Thiem (second round)

• 🇷🇺 Daniil Medvedev (quarterfinals)

• Stefanos Tsitsipas (semifinals)

• 🇩🇪 Alexander Zverev (second round)

• 🇮🇹 Matteo Berrettini (third round)

• 🇧🇪 David Goffin (third round)

• 🇪🇸 Roberto Bautista Agut (semifinals)

• 🇦🇷 Diego Schwartzman (second round)

• 🇷🇺 Andrey Rublev (first round)

• 🇷🇺 Karen Khachanov (third round)

• 🇨🇦 Denis Shapovalov (second round)

• Cristian Garín (first round)

• 🇧🇬 Grigor Dimitrov (second round)

• 🇨🇦 Félix Auger-Aliassime (second round)

• 🇺🇸 John Isner (third round)

Seeds
• # 🇫🇷 Gilles Simon (qualifying competition)

• # 🇫🇷 Jérémy Chardy (first round)

• # Pablo Cuevas (first round)

• # Aljaž Bedene (qualified)

• # 🇦🇷 Juan Ignacio Londero (first round)

• # 🇺🇸 Steve Johnson (first round)

• # 🇦🇺 Jordan Thompson (qualifying competition)

• # João Sousa (first round)

• # 🇲🇩 Radu Albot (first round)

• # 🇸🇪 Mikael Ymer (first round)

• # 🇧🇾 Egor Gerasimov (first round)

• # 🇰🇷 Kwon Soon-woo (qualifying competition)

• # 🇱🇹 Ričardas Berankis (qualified)

• # 🇮🇹 Jannik Sinner (first round)

• # 🇭🇺 Attila Balázs (first round)

• # 🇬🇧 Cameron Norrie (qualified)

• # 🇦🇷 Federico Delbonis (first round)

• # 🇮🇹 Gianluca Mager (first round)

• # 🇷🇸 Laslo Đere (first round)

• # 🇧🇷 Thiago Monteiro (qualifying competition, retired)

• # 🇭🇺 Márton Fucsovics (qualified)

• # 🇦🇹 Dennis Novak (qualifying competition)

• # 🇮🇹 Stefano Travaglia (first round)

• # 🇯🇵 Yūichi Sugita (first round)

Qualifiers
• # 🇺🇸 Sebastian Korda

• # 🇫🇮 Emil Ruusuvuori

• # 🇱🇹 Ričardas Berankis

• # Aljaž Bedene

• # 🇺🇸 Mackenzie McDonald

• # 🇭🇺 Márton Fucsovics

• # 🇮🇹 Salvatore Caruso

• # 🇬🇧 Cameron Norrie

• # 🇺🇸 Marcos Giron

• # Lloyd Harris

• # 🇺🇸 J. J. Wolf

• # 🇸🇰 Norbert Gombos