The 2024–25 Liga 3 is the fourth season of Portuguese football's third-tier league, following the reorganization which saw the Campeonato de Portugal moving one level down in the Portuguese football league system.

This competition consists of a first stage with all the teams then proceed to a promotion or relegation series depending on their performance.

In the first stage, the 20 clubs will be divided in two series (Série A and B) of 10 teams, according to geographic criteria.

The eight qualified teams of each series will playing against each other in a home-and-away double round-robin system.

The winners and runner-ups of the series will be automatically promoted to Liga Portugal 2.