Oonagh (or Una) is a significant figure in Irish mythology, renowned as the beautiful, glamorous, and sometimes tricky Queen of the Daoine Sidhe (Fairy Folk), wife to the fairy king Finvarra, known for her long golden hair, silver gown, and powerful illusions, often appearing in tales with Finn MacCool (as a giant's wife) or as a figure of nature, love, and transformation, symbolizing potent magic and feminine power. She is associated with glamour, illusion, animal protection, and trickery, embodying both beauty and danger, a classic fairy queen figure.

Key Aspects of Oonagh
- Appearance & Glamour: She's described with flowing golden hair, a silver gown bejeweled with dew, and is a master of illusions, capable of taking different forms, even turning into animals.
- Husband & Domicile: Wife of Finvarra (or Fionnbharr), King of the Fairies, they resided on hills like Knockma (Cnoc Meadha) or Knockshegouna.
- The Giant's Causeway Legend: In one prominent story, Oonagh uses her cunning to help her giant husband, Finn MacCool, defeat the Scottish giant Angus Benandonner by tricking Benandonner into thinking Finn was a baby.
- Goddess of Nature & Magic: She's seen as a goddess of love, nature (especially young animals), music, dance, and illusions, a powerful force within the Tuatha Dé Danann.
- Fairy Queen Archetype: Her tales touch on themes of love, betrayal (Finvarra's infidelity), protection, and the dangerous allure of the fairy world, influencing figures in ballads like "Tam Lin".
Symbolism & Modern Interpretations
- Oonagh represents potent magic, transformation, purity, and the power of feminine intelligence.
- She embodies the wild, enchanting, and sometimes perilous aspects of the Celtic fairy realm, influencing modern fantasy art and characters.