The 1978 Croke Cup was the 27th staging of the Croke Cup since its establishment by the Gaelic Athletic Association in 1944. The competition ran from 16 April to 7 May 1978.
St Colman's College were the defending champions, however, they were beaten by De La Salle College Waterford in the Harty Cup second round.
The final was played on 17 May 1978 at Nowlan Park in Kilkenny, between Templemore CBS and St Peter's College, in what was their first ever meeting in the final. Templemore CBS won the match by 2–11 to 1–04 to claim their first ever Croke Cup title.
Éamonn Cody was the top scorer with 2-02.