| Date: | 8 – 13 January |
| Edition: | 4th |
| Surface: | Hard (indoor) |
| Location: | Oeiras, Portugal |
| Champs: | Leandro Riedi |
| Champd: |  Karol Drzewiecki / Piotr Matuszewski |
| Before Name: | Oeiras Indoors |
| Before Year: | 2024 |
| Main Name: | Oeiras Indoors |
| After Name: | Oeiras Indoors |
The 2024 Oeiras Indoors II was a professional tennis tournament played on hard courts. It was the 4th edition of the tournament which was part of the 2024 ATP Challenger Tour. It took place in Oeiras, Portugal from 8 to 13 January 2024.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Spain | Alejandro Moro Cañas | 243 | 1 | |
| Henrique Rocha | 246 | 2 | ||
| João Sousa | 249 | 3 | ||
 Turkey | Cem İlkel | 255 | 5 | |
 United States | Martin Damm | 257 | 6 | |
 France | Maxime Janvier | 258 | 7 | |
| Leandro Riedi | 261 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry into the singles main draw using protected rankings:
The following players received entry into the singles main draw as special exempts:
The following players received entry from the qualifying draw:
Marius Copil
Aidan McHugh
Samuel Vincent Ruggeri
Michael VrbenskýThe following player received entry as a lucky loser:
See main article: 2024 Oeiras Indoors II – Singles.
Martin Damm 7–6(8–6), 6–2.See main article: 2024 Oeiras Indoors II – Doubles.
Karol Drzewiecki / Piotr Matuszewski def. 
Arjun Kadhe / Marcus Willis 6–3, 6–4.