2021 Serbia Open

The 2021 Serbia Open was a tennis tournament played on outdoor clay courts. It was the 5th and 1st edition of the event for male and female professional tennis players, respectively. It was part of the 2021 ATP Tour and the 2021 WTA Tour and took place in Belgrade, Serbia; in mid-April for men and mid-May for women. A second ATP tournament, called the Belgrade Open, was played in men's singles the week before the French Open.

Men's singles

 * 🇮🇹 Matteo Berrettini def. 🇷🇺 Aslan Karatsev, 6–1, 3–6, 7–6(7–0)

Women's singles

 * 🇪🇸 Paula Badosa def. Ana Konjuh 6–2, 2–0, ret.

Men's doubles

 * Ivan Sabanov / Matej Sabanov def.  Ariel Behar / 🇪🇨 Gonzalo Escobar, 6–3, 7–6(7–5)

Women's doubles

 * 🇷🇸 Aleksandra Krunić / 🇷🇸 Nina Stojanović def. 🇧🇪 Greet Minnen / 🇧🇪 Alison Van Uytvanck 6–0, 6–2

Prize money

 * per team

Seeds

 * 1 Rankings are as of 12 April 2021

Other entrants
The following players received wildcards into the main draw:
 * 🇷🇸 Nikola Milojević
 * 🇷🇸 Danilo Petrović
 * 🇷🇸 Viktor Troicki

The following players received entry from the qualifying draw:
 * 🇦🇷 Facundo Bagnis
 * 🇦🇷 Francisco Cerúndolo
 * 🇮🇹 Gianluca Mager
 * 🇫🇷 Arthur Rinderknech

The following players received entry as lucky losers:
 * 🇪🇸 Roberto Carballés Baena
 * 🇯🇵 Taro Daniel
 * João Sousa

Withdrawals

 * Before the tournament
 * Borna Ćorić → replaced by 🇦🇷 Federico Delbonis
 * Pablo Cuevas → replaced by João Sousa
 * 🇭🇺 Márton Fucsovics → replaced by 🇪🇸 Roberto Carballés Baena
 * 🇫🇷 Gaël Monfils → replaced by 🇦🇷 Federico Coria
 * 🇯🇵 Yoshihito Nishioka → replaced by 🇰🇷 Kwon Soon-woo
 * 🇫🇮 Emil Ruusuvuori → replaced by 🇯🇵 Taro Daniel
 * 🇦🇹 Dominic Thiem → replaced by 🇦🇷 Juan Ignacio Londero
 * 🇪🇸 Fernando Verdasco → replaced by 🇦🇺 Alexei Popyrin
 * 🇨🇿 Jiří Veselý → replaced by 🇮🇹 Marco Cecchinato
 * Stan Wawrinka → replaced by 🇱🇹 Ričardas Berankis

Seeds

 * Rankings are as of 12 April 2021

Other entrants
The following pairs received wildcards into the doubles main draw:
 * 🇷🇸 Miomir Kecmanović / 🇷🇸 Dušan Lajović
 * Ivan Sabanov / Matej Sabanov

The following pair received entry as an alternate:
 * 🇳🇿 Artem Sitak / 🇮🇹 Stefano Travaglia

Withdrawals

 * Before the tournament
 * Nikola Mektić / Mate Pavić → 🇳🇿 Artem Sitak / 🇮🇹 Stefano Travaglia
 * Hugo Nys / 🇩🇪 Tim Pütz → 🇮🇹 Matteo Berrettini / 🇮🇹 Andrea Vavassori

Retirements

 * 🇮🇳 Rohan Bopanna / Pablo Cuevas

Seeds

 * 1 Rankings are as of 10 May 2021

Other entrants
The following players received wildcards into the main draw:
 * 🇷🇸 Olga Danilović
 * 🇷🇸 Ivana Jorović
 * 🇷🇸 Lola Radivojević

The following players received entry using a protected ranking:
 * 🇷🇴 Mihaela Buzărnescu
 * 🇩🇪 Andrea Petkovic

The following players received entry from the qualifying draw:
 * 🇪🇸 Cristina Bucșa
 * 🇭🇺 Réka Luca Jani
 * Ana Konjuh
 * 🇨🇴 Camila Osorio
 * 🇷🇺 Kamilla Rakhimova
 * 🇨🇳 Wang Xiyu

The following player received entry as a lucky loser:
 * 🇧🇬 Viktoriya Tomova

Withdrawals

 * Before the tournament
 * Kiki Bertens → replaced by 🇧🇾 Aliaksandra Sasnovich
 * 🇷🇴 Sorana Cîrstea → replaced by Kaja Juvan
 * 🇫🇷 Fiona Ferro → replaced by 🇷🇺 Anna Kalinskaya
 * 🇷🇺 Svetlana Kuznetsova → replaced by 🇨🇿 Kristýna Plíšková
 * 🇵🇱 Magda Linette → replaced by 🇦🇺 Ajla Tomljanović
 * 🇷🇺 Anastasia Pavlyuchenkova → replaced by 🇧🇬 Viktoriya Tomova
 * 🇰🇿 Elena Rybakina → replaced by Polona Hercog
 * Anastasija Sevastova → replaced by 🇨🇿 Tereza Martincová
 * 🇩🇪 Laura Siegemund → replaced by 🇭🇺 Tímea Babos
 * Donna Vekić → replaced by 🇩🇪 Andrea Petkovic
 * 🇨🇳 Zheng Saisai → replaced by 🇷🇸 Nina Stojanović

Retirements

 * Ana Konjuh

Seeds

 * 1 Rankings as of May 10, 2021.

Other entrants
The following pairs received wildcard s into the doubles main draw:
 * 🇷🇸 Ivana Jorović / 🇷🇸 Lola Radivojević
 * 🇷🇸 Elena Milovanović / 🇷🇸 Dejana Radanović

The following pair received entry into the doubles main draw using a protected ranking:
 * 🇷🇺 Natela Dzalamidze / 🇷🇺 Irina Khromacheva

The following pair received entry as alternates:
 * 🇨🇴 Camila Osorio / 🇬🇧 Emily Webley-Smith

Withdrawals

 * Before the tournament
 * 🇪🇸 Aliona Bolsova / 🇮🇳 Ankita Raina → replaced by 🇷🇴 Mihaela Buzărnescu / 🇮🇳 Ankita Raina
 * 🇷🇺 Irina Khromacheva / 🇲🇪 Danka Kovinić → replaced by 🇷🇺 Natela Dzalamidze / 🇷🇺 Irina Khromacheva
 * 🇷🇸 Elena Milovanović / 🇷🇸 Dejana Radanović → replaced by 🇨🇴 Camila Osorio / 🇬🇧 Emily Webley-Smith
 * 🇷🇺 Anastasia Potapova / 🇷🇺 Vera Zvonareva → replaced by 🇭🇺 Tímea Babos / 🇷🇺 Vera Zvonareva