1978 All Ireland Under 21 Hurling Championship

The 1978 All-Ireland Under-21 Hurling Championship was the 15th staging of the All-Ireland Under-21 Hurling Championship since its establishment by the Gaelic Athletic Association in 1964.

Kilkenny were the defending champions, however, they were defeated in the provincial series.

On 29 October 1978, Galway won the championship following a 3-15 to 2-8 defeat of Tipperary in a replay of the All-Ireland final. This was their second All-Ireland title in the under-21 grade and their first in six championship seasons.