Which part of Ireland stays in the EU, Northern Ireland or the Republic of Ireland? - Quora

The Republic of Ireland.

These guys in green up there.

Both Republic of Ireland and United Kingdom (including Northern Ireland - the guys in red) used to be members of European Union until 23rd June 2016 referendum and UK’s choice to leave EU, thus bringing England, Wales, Scotland and Northern Ireland out of it.

Out of these five the only remaining member is Republic of Ireland.

Scotland is on the verge of (Br)exiting UK and re-joining EU.

The republic of Ireland is not a part of Great Britain, and will continue to be member of EU. Northern Ireland is a part of Great Britain and will leave EU. This constitutes one of the major problems brexit is causing. There is a large amount of people and goods crossing the border between these two parts of Ireland every day, without formalities. The introduction of strict passport control and customs regulations on goods crosing the border, will have a profound negative effect on the area.