Ireland

Ireland, officially the Republic of Ireland, was a country located in Europe before the Great War.

Fallout

 * Patrick the Celt is descended from Americanized Celts and keeps his heritage alive by collecting clothing, food, stories, songs, and knowledge of Celtic history. He knows the Irish song "Na Gheala Mbeadh."

Fallout 2

 * John L. Sullivan references Irish folklore and uses the phrase "Erin go bragh!"

Fallout 3

 * The armor worn by Reilly's Rangers includes a four-leaf clover on it, a symbol typically associated with the Irish.

Fallout 4

 * Irish Pride Industries shipyard is a location in Boston.
 * The Eddie Winter holotapes reference Irish gangs operating in the Boston area, as well as a trip to Ireland in holotape 9. Eddie also mentions attempting to further Irish/Italian relations in Boston before the war.
 * The Four Leaf Clover perk icon and the Shamrock Taphouse logo contain the national flag of Ireland.
 * Whiskey bottles in Fallout 4 are marked as Irish whiskey and have the word "whiskey" written in the Irish language.
 * Old Longfellow sings traditional Irish songs while idle.
 * In a recording made by Rebecca Linkowski and Gemma, the latter says, "Oh, Rebecca! That's very rebellious of you. Drinking in Paul Revere's house. I'll get my coat and a bottle of Irish!"
 * Like the one in Fallout 3, the Luck bobblehead in Fallout 4 has a four-leaf clover and an Irish buckle hat, a reference to the saying, "luck of the Irish."
 * The Four Leaf fishpacking plant name and logo refer to the four leaf clover.

Fallout 76

 * Uisce Beatha is a pre-War whiskey brand that was based in Ireland.
 * Skis found in Appalachia are the Ski-O-Matic brand, with a clover logo.

Known locations

 * Dublin (mentioned in Fallout 4)
 * Galway Bay (mentioned in Fallout 4)
 * Kilkenny (mentioned in Fallout 4)
 * Waterford (mentioned in Fallout 4)

Behind the scenes
In Fallout 4, the Brotherhood of Steel sail aboard The Prydwen, an armored airship that arrives in the Commonwealth from the Capital Wasteland. Prydwen was the name of King Arthur's ship used to sail to Ireland in Preiddeu Annwfn, a famous Welch poem.