1990 All Ireland Under 21 Hurling Championship

The 1990 All-Ireland Under-21 Hurling Championship was the 27th staging of the All-Ireland Under-21 Hurling Championship since its establishment by the Gaelic Athletic Association in 1964. The championship ended on 9 September 1990.

The championship was won by Kilkenny who secured the title following a 2-11 to 1-11 defeat of Tipperary in the All-Ireland final. This was their fifth All-Ireland title, their first in six championship seasons.

Tipperary were the defending champions.