Ossë:

One of the Maiar, Ossë, as as servant of Ulmo, is responsible for the ocean storms. His wife is Uinen. At one point he rebelled against Ulmo, apparently at the instigation of Melkor, though he was forgiven and went back to faithful service.

Olwë:

The King of the Teleri elves, Olwë lives within Alqualondë, the greatest haven of the Elves of Tol Eressëa. He was one of the three ambassadors for the Elves during the Ages of the Two Trees.

Óin:

One of the Thirteen Dwarves in the quest of Erebor, Óin survived the Battle of the Five Armies, only to die in the attempt to retake Moria. He was killed by the Watcher in the Water, as was recorded in the Book of Mazarbul.

Ori:

One of the dwarves accompanying Thorin on the quest of Erebor, Ori survived the battle of the Five Armies, and went with Balin to Moria. There he died in the attempt to retake the mines.

Oromë:

A Vala, Oromë is known as the Hunter. It was he who first found the Elves. Oromë hunts those monsters created by Morgoth. He rides the horse Nahar. Often, before the flight of the Noldor, he would return to Middle-Earth to hunt in the forests.

The Lord of the Rings
The Silmarillion
The Hobbit
The Complete Guide to Middle Earth by Robert Foster