Royal Irish Regiment may be either of two British Army regiments:
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Royal Irish Regiment (1684–1922)
The Royal Irish Regiment, until 1881 the 18th Regiment of Foot, was an infantry regiment of the line in the British Army, first raised in 1684. Also known as the 18th (Royal Irish) Regiment of Foot and the 18th (The Royal Irish) Regiment of Foot, ...
, also known as the 18th Regiment of Foot
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Royal Irish Regiment (1992), properly named the Royal Irish Regiment (27th (Inniskilling) 83rd and 87th and Ulster Defence Regiment)
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