2017–18 Slovenian Third League

The 2017–18 Slovenian Third League was the 26th edition of the Slovenian Third League. The season began on 19 August 2017 and ended on 27 May 2018.

Competition format and rules
The 2017–18 Slovenian Third League was divided into four regional groups with a total of 50 participating clubs. The three groups (North, Centre, East) were composed of 14 clubs, while the West group consisted of 8 clubs. The winners of the regular season in each group played a promotional two-legged play-off to decide the two teams promoting to the Slovenian Second League.

League table
1 Rakičan was denied licence.

Play-offs
A two-legged play-offs between the group winners for promotion to the 2018–19 Slovenian Second League.