The 2021 Antalya Challenger II was a professional tennis tournament played on clay courts. It was the second edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Antalya, Turkey between 1 and 7 February 2021.
The 2021 Garden Open was a professional tennis tournament played on clay courts. It was the twelfth edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Rome, Italy between 19 and 25 April 2021.
The 2021 Tallahassee Tennis Challenger was a professional tennis tournament played on green clay courts. It was the 21st edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Tallahassee, Florida, United States between 19 and 25 April 2021.
The 2021 Garden Open II was a professional tennis tournament played on clay courts. It was the thirteenth edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Rome, Italy between 26 April and 2 May 2021.
The 2021 I.ČLTK Prague Open was a professional tennis tournament played on outdoor clay courts. It was the ninth (men) and seventh (women) editions of the tournament which was part of the 2021 ATP Challenger Tour and the 2021 ITF Women's World Tennis Tour. It took place in Prague, Czech Republic from 3 to 9 May 2021.
The 2021 Internazionali di Tennis Città di Forlì was a professional tennis tournament played on clay courts. It was the second edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Forlì, Italy between 14 and 20 June 2021.
The 2021 President's Cup was a professional tennis tournament played on outdoor hard courts. It was the fifteenth and twelfth editions of the tournament which were part of the 2021 ATP Challenger Tour and the 2021 ITF Women's World Tennis Tour. It took place in Nur-Sultan, Kazakhstan between 12 and 18 July 2021.
The 2021 Internazionali di Tennis Città di Todi was a professional tennis tournament played on clay courts. It was the 15th edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Todi, Italy between 12 and 18 July 2021.
The 2021 Svijany Open was a professional tennis tournament played on clay courts. It was the 8th edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Liberec, Czech Republic between 2 and 8 August 2021.
The 2021 Platzmann-Sauerland Open was a professional tennis tournament played on clay courts. It was the first edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Lüdenscheid, Germany, between 16 and 22 August 2021.
The 2021 Internazionali di Tennis Città di Verona was a professional tennis tournament played on clay courts. It was the first edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Verona, Italy, between 16 and 22 August 2021.
The 2021 Columbus Challenger was a professional challenger level tennis tournament played on indoor hard courts. It was the tenth edition of the men's tournament which was part of the 2021 ATP Challenger Tour and the first edition of the women's event, that was part of 2021 WTA 125K series. It took place in Columbus, United States between 20 and 26 September 2021.
The 2021 Tennis Napoli Cup was a professional tennis tournament played on clay courts. It was the 20th edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Naples, Italy between 4 and 10 October 2021.
The 2021 Open Bogotá was a professional tennis tournament played on clay courts. It was the thirteenth edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Bogotá, Colombia between 18 and 24 October 2021.
The 2021 Lima Challenger II was a professional tennis tournament played on clay courts. It was the sixteenth edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Lima, Peru between 25 and 31 October 2021.
The 2021 Open International de Tennis de Roanne was a professional tennis tournament played on indoor hard courts. It was the first edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Roanne, France between 8 and 14 November 2021.
The 2021 Tali Open was a professional tennis tournament played on hard courts. It was the second edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Helsinki, Finland between November 15 and November 21, 2021.
The 2021 Città di Forlì II was a professional tennis tournament played on hard courts. It was the first edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Forlì, Italy between 29 November and 5 December 2021.
The 2021 Maia Challenger II was a professional tennis tournament played on clay courts. It was the fourth edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Maia, Portugal from 13 to 19 December 2021.
The 2021 Rio Tennis Classic was a professional tennis tournament played on hard courts. It was the second edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Rio de Janeiro, Brazil from 13 to 19 December 2021.
Francisco Cerúndolo 
Orlando Luz / 
