| Date: | 15 – 21 March |
| Edition: | 13th |
| Category: | WTA 250 |
| Draw: | 32S / 16D |
| Surface: | Hard |
| Prize Money: | $235,238 |
| Location: | Monterrey, Mexico |
| Venue: | Club Sonoma |
| Champs: |  Leylah Annie Fernandez |
| Champd: |  Caroline Dolehide / Asia Muhammad |
The 2021 Monterrey Open (also known as the Abierto GNP Seguros for sponsorship reasons) was a women's tennis tournament played on outdoor hard courts. It was the 13th edition of the Monterrey Open and a WTA 250 tournament on the 2021 WTA Tour. It took place at the Club Sonoma in Monterrey, Mexico, from 15 to 21 March 2021.[1]
See main article: article and 2021 Monterrey Open – Singles.
Leylah Annie Fernandez def. Viktorija Golubic, 6–1, 6–4.This was Fernandez's first WTA tour title.
See main article: article and 2021 Monterrey Open – Doubles.
Caroline Dolehide / Asia Muhammad def. 
Heather Watson / 
Saisai Zheng 6–2, 6–3.| Event | W | F | SF | QF | Round of 16 | Round of 32 | width=85 | Q | width=85 | Q2 | width=85 | Q1 |
| Singles | 280 | 180 | 110 | 60 | 30 | 1 | 18 | 12 | 1 | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubles | 1 |
| Event | W | F | SF | QF | Round of 16 | Round of 32 | width=85 | Q2 | width=85 | Q1 |
| Singles | $29,200 | $16,398 | $10,100 | $5,800 | $3,675 | $2,675 | $1,950 | $1,270 | ||
| Doubles* | $10,300 | $6,000 | $3,800 | $2,300 | $1,750 |
| Country | Player | Ranking1 | Seed |
|---|---|---|---|
| United States | Sloane Stephens | 44 | 1 |
 Argentina | Nadia Podoroska | 46 | 2 |
| China | Zheng Saisai | 48 | 3 |
 Czech Republic | |||
| United Kingdom | Heather Watson | 64 | 5 |
 Russian Federation | Anna Blinkova | 70 | 6 |
 Spain | Sara Sorribes Tormo | 71 | 7 |
| United States | Ann Li | 72 | 8 |
 Japan | Nao Hibino | 79 | 9 |
The following players received wildcards into the main draw:
The following player received entry into the singles main draw using a protected ranking:
The following player received entry as a special exempt:
The following players received entry from the qualifying draw:
The following players received entry as lucky losers:
Victoria Azarenka → replaced by 
Jasmine Paolini Marie Bouzková → replaced by 
Kristína Kučová Coco Gauff → replaced by Varvara Gracheva
Nina Stojanović
Ons Jabeur → replaced by Anna Karolína Schmiedlová Johanna Konta → replaced by Tamara Zidanšek
Danka Kovinić → replaced by Harriet Dart
Magda Linette → replaced by Martina Trevisan
Ajla Tomljanović → replaced by Zhu Lin| Country | Player | Country | Player | Rank1 | Seed | |
|---|---|---|---|---|---|---|
| United States | Desirae Krawczyk |  Mexico | Giuliana Olmos | 76 | 1 | |
| United States | Caroline Dolehide | United States | Asia Muhammad | 82 | 2 | |
| Arantxa Rus | Tamara Zidanšek | 121 | 3 | |||
| Spain | Lara Arruabarrena | Australia | Ellen Perez | 135 | 4 |
The following pairs received wildcards into the doubles main draw:
Marie Bouzková / Sara Sorribes Tormo → replaced by Paula Kania-Choduń / Katarzyna Piter Anna Kalinskaya / Viktória Kužmová → replaced by 
Greet Minnen / Ingrid Neel Anna Blinkova / Nadia Podoroska (right hip injury) Greet Minnen / Ingrid Neel (gastrointestinal illness)
