| Date: | 12–18 October |
| Edition: | 4th |
| Surface: | Clay |
| Location: | Lisbon, Portugal |
| Champs: |  Jaume Munar |
| Champd: |  Roberto Cid Subervi / Gonçalo Oliveira |
The 2020 Lisboa Belém Open was a professional tennis tournament played on clay courts. It was the fourth edition of the tournament which was part of the 2020 ATP Challenger Tour. It took place in Lisbon, Portugal between 12 and 18 October 2020.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
| Spain | Jaume Munar | 109 | 1 | |
| Pedro Sousa | 113 | 2 | ||
 Bosnia and Herzegovina | Damir Džumhur | 114 | 3 | |
 Italy | Paolo Lorenzi | 130 | 4 | |
| Italy | Federico Gaio | 132 | 5 | |
| Tallon Griekspoor | 139 | 6 | ||
| Blaž Rola | 148 | 7 | ||
| João Domingues | 161 | 8 |
The following players received wildcards into the singles main draw:
The following player received entry into the singles main draw as a special exempt:
The following players received entry from the qualifying draw:
See main article: 2020 Lisboa Belém Open – Singles.
Jaume Munar def. Pedro Sousa 7–6(7–3), 6–2.See main article: 2020 Lisboa Belém Open – Doubles.
Roberto Cid Subervi / Gonçalo Oliveira def. 
Harri Heliövaara / 
Zdeněk Kolář 7–6(7–5), 4–6, [10–4].
