- Yggdrasill = Óðinn's horse. The world-tree.
- Yggur = One of Óðinn's names.
- Ylur = Warmth.
- Ýmir = Name of a giant. "And when the sky and the breeze of the heat met, so that everything melted and dripped, then the drops came alive with the power of the one who sent the heat, and started to look like a man. He was called Ýmir, but the frost-giants call him Aurgelmir. All the frost-giants originated in this way."
- Ymsi = Name of a giant.
- Yrðlingur = Fox cub.
- Ýringur = Name of a giant. Bright spots on a dark horse.