Eithne (earlier Ethniu, Ethliu, Ethlinn and a variety of other spellings - see below) is a popular Irish female name meaning 'little fire' and is borne by a variety of historical and legendary figures, including:
- Ethniu, daughter of Balor and mother of Lug in Irish mythology
- Eithne, daughter of the king of Alba, wife of the High King Fiacha Finnfolaidh and mother of Tuathal Teachtmhar
- Eithne, the mother of Saint Columba
- LÉ Eithne (P31), a ship in the Irish Naval Service
- Enya (Eithne Ní Bhraonáin), musician
Other spellings and earlier forms include: Ethnea, Ethlend, Ethnen, Ethlenn, Ethnenn, Ethne, Aithne, Enya, Áine (sometimes a separate name), Ena, Etney, Eithnenn, Eithlenn, Eithna, Ethni, Edlend, Edlenn.
