The 2018–19 NIFL Championship was contested by 12 teams.
Institute were champions in the
previous season, and were promoted to the
2018–19 NIFL Premiership. They were replaced by the bottom team in last season's Premiership,
Ballinamallard United. Runners-up
Newry City won 6–3 on aggregate in the
promotion play-off against
Carrick Rangers, also achieving promotion to the Premiership for this season and relegating Carrick Rangers to the Championship. The bottom team from the previous season,
Lurgan Celtic, were relegated to the third-tier
NIFL Premier Intermediate League. They were replaced by
Dundela, winners of the Premier Intermediate League. The eleventh-placed team from the previous season,
Dergview, remained in the Championship this season, after defeating the NIFL Premier Intermediate League runners-up
Queen's University 4–1 on aggregate in the relegation play-off.
Stadia and locations ==League table==