2021 Singapore Tennis Open

The 2021 Singapore Tennis Open is a tournament on the 2021 ATP Tour. It is played on indoor hard courts in Singapore. It is organised with a single-year licence in 2021, and was held at OCBC Arena in Singapore from February 22 to February 28, 2021.

Singles

 * 🇦🇺 Alexei Popyrin def. 🇰🇿 Alexander Bublik, 4–6, 6–0, 6–2.

Doubles

 * 🇧🇪 Sander Gillé / 🇧🇪 Joran Vliegen def. 🇦🇺 Matthew Ebden / 🇦🇺 John-Patrick Smith, 6–2, 6–3.

Prize money

 * per team

Seeds

 * 1 Rankings are as of February 15, 2021

Other entrants
The following players received wildcards into the main draw:
 * 🇧🇬 Adrian Andreev
 * 🇦🇺 Matthew Ebden
 * 🇯🇵 Shintaro Mochizuki

The following player received an entry using a protected ranking into the main draw:
 * 🇮🇳 Yuki Bhambri

The following players received entry from the qualifying draw:
 * 🇹🇷 Altuğ Çelikbilek
 * 🇺🇸 Christopher Eubanks
 * 🇺🇸 Thai-Son Kwiatkowski
 * 🇦🇺 John-Patrick Smith

Withdrawals

 * 🇨🇦 Félix Auger-Aliassime → replaced by 🇦🇺 Alexei Popyrin
 * 🇱🇹 Ričardas Berankis → replaced by 🇦🇺 Marc Polmans
 * 🇫🇷 Jérémy Chardy → replaced by Ernests Gulbis
 * 🇬🇧 Daniel Evans → replaced by 🇯🇵 Yasutaka Uchiyama
 * 🇬🇧 Cameron Norrie → replaced by 🇯🇵 Taro Daniel
 * 🇨🇦 Vasek Pospisil → replaced by 🇦🇺 James Duckworth
 * 🇳🇴 Casper Ruud → replaced by Jason Jung
 * 🇫🇮 Emil Ruusuvuori → replaced by 🇮🇹 Roberto Marcora
 * 🇯🇵 Yūichi Sugita → replaced by 🇮🇳 Yuki Bhambri
 * 🇮🇹 Stefano Travaglia → replaced by 🇺🇸 Maxime Cressy

Seeds

 * Rankings are as of February 15, 2021.

Other entrants
The following pairs received wildcards into the doubles main draw:
 * 🇸🇬 Shaheed Alam / 🇸🇬 Roy Hobbs
 * 🇺🇸 James Cerretani / 🇨🇦 Adil Shamasdin

Withdrawals

 * Before the tournament
 * 🇬🇧 Dan Evans / 🇬🇧 Lloyd Glasspool → replaced by 🇮🇳 Purav Raja / 🇮🇳 Ramkumar Ramanathan
 * 🇲🇩 Radu Albot / Ričardas Berankis → replaced by 🇺🇸 Robert Galloway / 🇺🇸 Alex Lawson
 * 🇫🇮 Harri Heliövaara / 🇫🇮 Emil Ruusuvuori → replaced by 🇯🇵 Taro Daniel / Jason Jung
 * Lloyd Harris / 🇮🇹 Stefano Travaglia → replaced by 🇺🇸 Evan King / 🇺🇸 Hunter Reese
 * 🇫🇷 Jérémy Chardy / 🇫🇷 Fabrice Martin → replaced by 🇮🇳 Sriram Balaji / Luca Margaroli
 * Treat Huey / Christopher Rungkat → replaced by 🇺🇸 Thai-Son Kwiatkowski / 🇺🇸 Christopher Eubanks
 * During the tournament
 * 🇰🇷 Kwon Soon-woo / 🇯🇵 Yasutaka Uchiyama