Irish, of uncertain etymology. Derivation is possibly from the male name Owen [via the Irish male names Eoghan or Abhainn]. Winifred is an Anglicized form.

It is possible that the name originates from úan, "lamb" in Irish Gaelic. It may be derived from transliteration of Una, Latin feminine for "one", and thus cognate with Unity. However there is some dispute and it is more usually seen as an Anglicized form of the Gaelic forms Úna/Ùna [q.v.].