The 2018–19 Irish Cup (known as the Tennent’s Irish Cup for sponsorship purposes) was the 139th edition of the premier knock-out cup competition in Northern Irishfootball. The competition began on 11 August 2018 and concluded with the final at Windsor Park on 4 May 2019.
Coleraine were the defending champions, having defeated Cliftonville in the 2018 final. Crusaders were the eventual winners, defeating second-tier side Ballinamallard United 3–0 in the final to lift the Cup for the fourth time overall, and the first time in the 10 years since winning the 2009 final.
All ties level after 90 minutes used extra time to determine the winner, with a penalty shoot-out to follow if necessary.
126 clubs entered this season’s competition – a reduction of four clubs compared with the 2017–18 total of 130 clubs. 90 regional league clubs from tiers 4–7 in the Northern Ireland football league system entered the competition in the first round, with 76 of them drawn into 38 first round fixtures and the remaining 14 clubs receiving a bye into the second round. The 38 first-round winners were joined by the 14 byes and the 12 clubs of the NIFL Premier Intermediate League in the second round. After two further rounds, the eight surviving clubs joined the 24 senior NIFL Premiership and NIFL Championship clubs in the fifth round. All ties level after 90 minutes used extra time to determine the winner, with a penalty shoot-out to follow if necessary.