It ran from 12 August 2017 to 4 May 2018 and Dundela were crowned as champions, winning promotion to the 2018–19 NIFL Championship.
Twelve teams competed in the league.
Armagh City and Annagh United from were relegated the 2016–17 NIFL Championship and Portstewart were promoted as the winners of the 2016–17 Northern Ireland Intermediate League.
The eleventh-placed team from the Championship, Dergview, played the runners-up from the 2017–18 Premier Intermediate League, Queen's University, over two legs for one spot in the NIFL Championship.
Dergiew won 4-1 on aggregate and retained their position in the NIFL Championship with Queen's University remaining in the NIFL Premier Intermediate League.