Éogan or Eógan is an early Irish male name, which also has the hypocoristic and diminutive forms Eóganán, Eóghainin, Eóghain and Eóghainn. In more modern forms of Irish it is written as Eóghan or Eoghan (/'oːəun/). It is often associated with the Greek name Eugenes, meaning "noble born".Etymologists disagree as to the origin of Eoghan. The encyclopedia Irish Names (1981, 1990) derives the name from Old Irish Eógan, meaning 'born of the yew', the Corpus Inscriptionum Insularum Celticarum from Primitive Irish *Iwagenas, while others such as Tomás Ua Concheanainn (Mion-chomhradh, 1903) have stated that Eóghan equates to Owain and Eugene, and Dr. Rachel Bromwich has commented that Eoghan is a derivation of the Latin Eugenius.
The name corresponds to the Welsh Owain, often spelt Owen in English; as well to Ewen, Ewan and Euan.