| Date: | 30 August – 5 September |
| Edition: | 3rd |
| Surface: | Hard |
| Location: | Manacor, Spain |
| Champs: |  Lukáš Lacko |
| Champd: |  Karol Drzewiecki /  Sergio Martos Gornés |
| Before Year: | 2019 |
| Before Name: | Rafa Nadal Open Banc Sabadell |
The 2021 Rafa Nadal Open was a professional tennis tournament played on hard courts. It was the third edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Manacor, Spain between 30 August and 5 September 2021.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Japan | Yasutaka Uchiyama | 123 | 1 | |
| Spain | Fernando Verdasco | 132 | 2 | |
 United Kingdom | Liam Broady | 147 | 3 | |
| João Sousa | 149 | 4 | ||
 Austria | Sebastian Ofner | 166 | 5 | |
| Marcelo Tomás Barrios Vera | 172 | 6 | ||
| Poland | Kacper Żuk | 173 | 7 | |
| Blaž Rola | 179 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry into the singles main draw as alternates:
The following players received entry from the qualifying draw:
The following players received entry as lucky losers:
See main article: 2021 Rafa Nadal Open – Singles.
Lukáš Lacko def. Yasutaka Uchiyama 5–7, 7–6(10–8), 6–1.See main article: 2021 Rafa Nadal Open – Doubles.
Karol Drzewiecki / Sergio Martos Gornés def. 
Fernando Romboli / Jan Zieliński 6–4, 4–6, [10–3].
