| Date: | 26 October – 1 November |
| Edition: | 3rd |
| Surface: | Clay |
| Location: | Marbella, Spain |
| Champs: |  Pedro Martínez |
| Champd: | Gerard Granollers / Pedro Martínez |
| Before Name: | Casino Admiral Trophy |
| After Name: | Andalucía Challenger |
The 2020 Marbella Tennis Open was a professional tennis tournament played on clay courts. It was the third edition of the tournament which was part of the 2020 ATP Challenger Tour. It took place in Marbella, Spain between 26 October and 1 November 2020.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Argentina | Federico Coria | 86 | 1 | |
| Spain | Pedro Martínez | 92 | 2 | |
 Italy | Gianluca Mager | 96 | 3 | |
| Spain | Roberto Carballés Baena | 99 | 4 | |
 Slovakia | Andrej Martin | 102 | 5 | |
| Spain | Jaume Munar | 108 | 6 | |
| Pedro Sousa | 110 | 7 | ||
| Slovakia | Jozef Kovalík | 125 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry into the singles main draw using a protected ranking:
The following players received entry into the singles main draw as alternates:
The following players received entry from the qualifying draw:
See main article: 2020 Marbella Tennis Open – Singles.
Pedro Martínez def. Jaume Munar 7–6(7–4), 6–2.See main article: 2020 Marbella Tennis Open – Doubles.
Gerard Granollers / Pedro Martínez def. 
Luis David Martínez / 
Fernando Romboli 6–3, 6–4.
