2021 Reinert Open

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.

Seeds

 * 1 Rankings are as of 19 July 2021.

Other entrants
The following players received wildcards into the singles main draw:
 * 🇩🇪 Noma Noha Akugue
 * 🇩🇪 Nicole Rivkin
 * 🇩🇪 Nastasja Schunk
 * 🇩🇪 Joëlle Steur

The following players received entry using protected rankings:
 * 🇦🇺 Jaimee Fourlis
 * 🇩🇪 Katharina Hobgarski
 * 🇩🇪 Anna Zaja

The following players received entry from the qualifying draw:
 * 🇮🇹 Federica Arcidiacono
 * Kamilla Bartone
 * 🇪🇸 Jéssica Bouzas Maneiro
 * 🇮🇹 Cristiana Ferrando
 * 🇺🇸 Elizabeth Halbauer
 * Arianne Hartono
 * 🇩🇪 Anna Klasen
 * 🇷🇺 Ekaterina Makarova

The following player received entry as a lucky loser:
 * 🇷🇺 Elina Avanesyan

Singles

 * 🇷🇺 Elina Avanesyan def. 🇮🇹 Federica Di Sarra, 6–7(4–7), 6–2, 6–2

Doubles

 * 🇰🇿 Anna Danilina / 🇺🇦 Valeriya Strakhova def. 🇸🇪 Mirjam Björklund / 🇦🇺 Jaimee Fourlis, 4–6, 7–5, [10–4]