This article is about the meaning of Erin, for other uses see Erin (disambiguation).

Erin is a Hiberno-English derivative of Irish Gaelic Éirinn, the dative case - and also locative case - of Éire, the Irish word for "Ireland". Poets and also nineteenth-century Irish nationalists also used Erin in English as a romantic name for Ireland, as shown in the catchphrase (when speaking of Ireland's experiences with Britain), "Let Erin Remember". According to Irish mythology and folklore, the name was given to the land by the Milesians after the goddess Ériu. Erin Go Bragh (Éirinn Go Brách, in standard orthography), often heard during St. Patrick's Day, means "Ireland Forever". The etymological history of the word as it drifted throughout the Gaelic region gave rise to its use by the early Scots to both mean "Ireland", as well as "West", as Ireland lay to the geographic west of Scotland.

Erin is a popular modern name for both sexes, more so for females than for males. However, alterations in the spelling will distinguish between male or female. Alternatively spelled as Eryn, Erynn, Eirinn, Aeryn, Eiryne. It also contributed to many surnames, as well, for example "Erin-Vienne" (West Man/Irish Man) gave rise to the surnames of Irving, Irvine, Ervin, Irwin, Eryvine, Ervyne, etc. There are over 200 known derivations of the Erin root.