The Montenegrin Third League (Montenegrin: Treća crnogorska liga / Трећа црногорска лига) is the third and lowest-tier football league in Montenegro. It is headed by the regional unions of the Football Association of Montenegro (Union of the clubs - North, Union of the clubs - Center, Union of the clubs - South), under the Football Association of Montenegro. In the 2025–26 season, 28 teams participated, divided into three regions. The top team from each region qualifies for the playoff from which the top team qualify for the Montenegrin Second League.

For the 2023–24 season, Third league is divided in three geographical regions. Nine teams compete in the North, fourteen in the Center, and eight in the South.

The Third League - North is organised by Union of the clubs - North (covering municipalities of Pljevlja, Bijelo Polje, Berane, Rožaje, Plav, Petnjica, Gusinje, Mojkovac, Andrijevica, Žabljak, Šavnik and Plužine). For the 2023–24 season, there are nine teams competing in the North Region.

The Third League - Center is organised by Union of the clubs - Center (Montenegrin: Udruženje klubova - Centar - FSCG). The Central region includes the municipalities of Podgorica (capital city), Nikšić, Danilovgrad, Šavnik, Plužine, Kolašin and Tuzi.

There are 14 clubs competing in Montenegrin Third League - Center for the 2023–24 season.

The Third League - South is organised by Union of the clubs - South (Montenegrin: Udruženje klubova - Jug - FSCG). The municipalities within Southern region include: Cetinje, Kotor, Herceg Novi, Tivat, Budva, Bar and Ulcinj.

For the 2023–24 season, there are seven teams competing in the South region.

Regional leagues as a lowest-tier competition in Montenegro, were founded in 1968. The format and system of competition has not changed. From 1968 to 2006, it was the fourth or fifth level of competition in SFR Yugoslavia, FR Yugoslavia and Serbia and Montenegro. Following Montenegrin independence (2006), regional leagues became the third tier in the organisation of domestic football competitions.
From 1968 until now, the league is divided on three regions - North (clubs from territories of Berane, Bijelo Polje, Gusinje, Mojkovac, Petnjica, Plav, Pljevlja, Rožaje and Žabljak) Center (Podgorica with Golubovci and Tuzi, Danilovgrad, Kolašin, Nikšić, Plužine and Šavnik) and South (Bar, Budva, Cetinje, Herceg Novi, Kotor, Tivat and Ulcinj).
At period 1961–2006, winners of three regional leagues were promoted to Montenegrin Republic League (3rd tier) or played Montenegrin football playoffs.