The 2021 Brest Challenger was a professional tennis tournament played on hard courts. It was the sixth edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Brest, France between 25 and 31 October 2021.

Singles main-draw entrants Seeds Country Player Rank1 SeedArthur Rinderknech651Jenson Brooksby702Richard Gasquet743Brandon Nakashima794Stefano Travaglia835Pierre-Hugues Herbert976Henri Laaksonen997Hugo Gaston1068 1 Rankings are as of 18 October 2021.

Other entrants The following players received wildcards into the singles main draw: Manuel Guinard Arthur Rinderknech Luca Van Assche

The following player received entry into the singles main draw as a special exempt: Carlos Taberner

The following player received entry into the singles main draw as an alternate: Maxime Janvier

The following players received entry from the qualifying draw: Kenny de Schepper Aleksandr Nedovyesov Zsombor Piros Alexey Vatutin

The following player received entry as a lucky loser: Valentin Royer

Champions Singles

Brandon Nakashima def. João Sousa 6–3, 6–3.

Doubles

Sadio Doumbia / Fabien Reboul def. Salvatore Caruso / Federico Gaio 4–6, 6–3, [10–3].

References