There is no Irish nationalist anthem titled "Ireland Ireland." The official national anthem of Ireland is "Amhrán na bhFiann" ("The Soldier's Song").
Sinne Fianna Fáil
atá faoi gheall ag Éirinn,
buíon dár slua
thar toinn do ráinig chugainn,
faoi mhóid bheith saor
seantír sinn feasta,
caithfimid an cath
le hÉirinn go brách."Soldiers are we,
whose lives are pledged to Ireland,
some have come
from a land beyond the wave,
sworn to be free,
no more our ancient sireland
shall shelter the despot or the slave.
Tonight we man the gap of danger,
for Ireland, for ever."
If you heard "Ireland Ireland," it may be a misheard lyric, a sports chant, or a modern composition—not the national anthem.