The defending champions were Linfield, who defeated Ballymena United 3–1 in the 1977–78 final.[1] However, they were knocked out by eventual winners Cliftonville in the first round. Cliftonville went on to win the cup for the 8th time, defeating Portadown 3–2 in the final. The 1979 victory represented their first cup success in 70 years; this remains a record for the longest gap between Irish Cup wins.[2] This was Cliftonville's last Irish Cup success until the club won the Irish Cup for the first time in 45 years in 2024, though they had reached the final five times since this win; in 1997, 1999, 2009, 2013 and 2018. They lost the 1997, 2009, 2013 and 2018 finals, and were disqualified before the final was played in 1999 when it was discovered that they had fielded an ineligible player in the earlier rounds.
