The largest Protestant denomination is the Church of Ireland (having roughly 365,000 members, making up around 3% of the population of the Republic of Ireland, 15% of Northern Ireland, and 6.3% of the whole of Ireland), followed by the Presbyterian Church, with a membership of around 300,000, accounting for 0.6% of people in the Republic and 20% in Northern Ireland (6.1% of Ireland's population).
The largest Christian group in Ireland is the Church of Ireland, with around 365,000 adherents, making up roughly 3% of the population, while the Presbyterian Church has about 300,000 members, accounting for approximately 0.6% in the Republic and 20% in Northern Ireland (around 6.1% overall).