Ulmo is one of the Valar. He is counted as one of the Aratar, the most powerful of the Valar. His name means ‘The Pourer’ or ‘The Rainer’. He is also known as the Lord of the Waters, and the King of the Seas. He governs all seas, rivers, lakes, fountains and springs. Because of this, the Elves say that the spirit of Ulmo runs in all the veins of Middle-earth. In this way all news of need and grief comes to Ulmo, which would otherwise be hidden from Manwë.

Ulmo never dwells in one place for too long, and he rarely appears on land, not even to attend the councils of the Valar unless they debated great matters. He lives in the Outer Ocean.

He loves both Men and Elves. Ulmo bore the horns of Ulumúri, which were made by Salmar, none can forget their music, and they also express glory and sadness.

He appeared to Tuor and told him to look for the Hidden Kingdom of Gondolin, ruled by King Turgon. He gave Tuor a cloak that would shield him from enemy eyes. Ulmo is known for helping to keep Gondolin hidden with his power in the Vale of Sirion.

Ulmo also saved Elwing when she cast herself into the sea by giving her the form of a white bird.

Ulmo was taught more music by Eru than any of the Ainur, therefore he instructed the Teleri in music, thus making them the fairest singers among the Elves.