Republic of Ireland   Hi Wardhog The official name of the state of Ireland is Ireland see Article  of the Constitution of Ireland Republic of Ireland is the description of the state see Article  of the Republic of Ireland Act  The Republic of Ireland Act was the statutory device used to remove the British monarchy from southern Irish politics It did not change the name of the state that would have required a constitutional change as thus the state is referred to formally as Ireland such as in EU treaties the UN etc That Ireland is the name of the state is further reinforced through treaties between the UK and Irish states which agree to use each jurisdictions respective proper name in relations with each other Formerly UK authorities frequently referred to Ireland as the Republic of Ireland most notably on extradition requests which were rejected as invalid in the Irish supreme court on that basis