Ireland is the only country in the world where there lived more people 200 years ago than today. And the difference is rather large in 1840 the island had 8,2 million inhabitants while today it hosts merely 5,6 million. The Irish were forced out from their homeland by poverty and malnutrition.
Prior to World War 2 no Lithuanians would have even considered moving to Ireland which was at the time poorer than Lithuania. Sadly, the subsequent decades of Soviet occupation and genocide in Lithuania (1940-1990) changed all this and Ireland left Lithuania far behind economically. After 1990 Lithuanian independence and 2004 EU membership permitted easy migration tens of thousands chose the English-speaking Ireland to start hopefully richer lives there.
The young age of Lithuanian-Irish community means there are no imposing centuries-old Lithuanian halls, cemeteries or churches in Ireland (unlike the US megalopolises). Lithuanian mass is however celebrated weekly in Dublin at St. Andrew church (Westland Row 2), there are some Lithuanian shops and restaurants.
Republic of Ireland census of 2011 revealed that there are 36 683 citizens of Lithuania living there (0,82% of total population) and 31 635 native speakers of Lithuanian (0,7%; the third linguistic minority in size after Polish and French). 10% of all Lithuanian emigrants today leave for Ireland.
Lithuanian citizens are quite evenly spread across the country. By the sheer numbers, most of them live in Dublin (10 576, 0,85% of Dubliners). Castleknock is the most Lithuanian district with ~10% of its population Lithuanian citizens.
There are daily plane services between Lithuanian and Irish cities but the frequencies have been decreasing. The financial crisis in Ireland itself may have attributed to this.