The 2023 Lisboa Belém Open was a professional tennis tournament played on outdoor clay courts.

It was the seventh (men) and third (women) editions of the tournament which were part of the 2023 ATP Challenger Tour and the 2023 ITF Women's World Tennis Tour.

It took place in Lisbon, Portugal between 2 and 8 October 2023.

It was Pedro Sousa last professional event before he retired.

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: The following players received entry as lucky losers: The following players received wildcards into the singles main draw: The following players received entry from the qualifying draw: The following players received entry as lucky losers: