1966 All-Ireland Under-21 Hurling Championship

The 1966 All-Ireland Under-21 Hurling Championship was the third staging of the All-Ireland Under-21 Championship since its establishment by the Gaelic Athletic Association in 1964. The championship began on 27 March 1966 and ended on 3 November 1966

Wexford entered the championship as the defending champions.

The All-Ireland final, the only one to have gone to two replays, was eventually decided on 3 November 1966 at Croke Park in Dublin, between Cork and Wexford, in what was their first ever championship meeting. Cork won the match by 9-09 to 5-09 to claim their first championship title.

Cork's Charlie McCarthy and Seánie Barry were the championship's top scorers.