Niamh of the Golden Hair was a faery princess who loved the bard Oisin and led him away to Tir nan og.
From Lady Gregory's Gods and Fighting Men:
"And it was not long till they saw coming twoards them from the west a beautiful young woman, riding on a very fast slender white horse. A queen's crown she had on her head, and a dark cloak of silk down to the ground, having stars of red gold on it; and her eyes were blue and as clear as the dew on the grass, and a gold ring hanging down from every golden lock of her hair; and her cheeks redder than the rose, and her skin whiter than the swan upon the wave, and her lips as sweet as honey that is mixed through red wine."