The 2021 Reinert Open was a professional women's tennis tournament played on outdoor clay courts.

It was the thirteenth edition of the tournament which was part of the 2021 ITF Women's World Tennis Tour.

It took place in Versmold, Germany between 26 July and 1 August 2021.

[1] The following players received wildcards into the singles main draw: The following players received entry using protected rankings: The following players received entry from the qualifying draw: The following player received entry as a lucky loser: