2023–24 Third Football League (Croatia)

The 2023–24 Croatian Third Football League (also known as Treća Nogometna Liga and 3. NL) is the 33rd edition of the fourth tier of Croatian football league and 2nd season of the restructured Treća nogometna liga.

2022–23 season was the first season, 2023–24 season being the second, where fourth tier competition is named Third Football League, and the first season where fourth tier competition was the highest competition divided in groups (traditionally it being third tier competition).

Winner of every group will qualify for the promotion qualifications, as well as the 14th placed team in Second Football League. Those six teams battled for 3 open spots in next seasons' Second Football League.

Teams
The league is contested in 5 groups, based on geographic locations, by between 10 and 18 teams. Groups are based on centers: Varaždin (North), Rijeka (West), Zagreb (Center), Osijek (East) and Split (South).

Promotion play-offs

 * }

No club that finished in the top 3 in North division obtained license for 2. NL. Because of this, 14th placed team in the 2.NL did not have to play relegation play-off. 4 other group winners played for the remaining 2 spots in 2024-25 Second Football League.