2017–18 NIFL Championship

The 2017–18 NIFL Championship will be the second season of the second-tier Irish League since gaining senior status.

Teams
The 2017–18 NIFL Championship will consist of 12 teams. Warrenpoint Town were champions in the previous season and were promoted to the 2017–18 NIFL Premiership. The winners of the promotion pre-play-off, second-placed finishers Institute were defeated by Carrick Rangers in the Premiership play-off, therefore failing to achieve promotion.

The bottom team from the previous season, Annagh United was relegated to the third-tier NIFL Premier Intermediate League. They were replaced by Limavady United, winners of the Premier Intermediate League. In addition, second from bottom team from the previous season, Armagh City were relegated and replaced by third-tier runners-up Newry City A.F.C., against whom they lost a two-legged play-off.

Matches 1–22
During matches 1–22 each team played every other team twice (home-and-away).

Matches 23–32
During matches 23–32 each team played every other team in their half of the table twice (home-and-away).

NIFL Premiership play-offs
The second and third-placed teams from the Championship, will take part in the Premiership pre-play-off. The winners will then play the second-bottom-placed team in the 2017-18 NIFL Premiership in the play-off.

NIFL Championship play-off
The eleventh-placed team from the Championship will play the runners-up from the 2017–18 Premier Intermediate League over two legs for one spot in the 2018–19 NIFL Championship.