The 1984 All-Ireland Under-21 Hurling Championship was the 21st staging of the All-Ireland Under-21 Hurling Championship since its establishment by the Gaelic Athletic Association in 1964.
Galway were the defending champions, however, they were beaten by Tipperary in the All-Ireland semi-final.
On 22 August 1984, Kilkenny won the championship following a 1-12 to 0-11 defeat of Tipperary in the All-Ireland final. This was their fourth All-Ireland title in the under-21 grade and their first in seven championship seasons.
Results.
Leinster Under-21 Hurling Championship.
Final
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Munster Under-21 Hurling Championship.
First round
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Semi-finals
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Final
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All-Ireland Under-21 Hurling Championship.
Semi-finals
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Final
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References.
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