In J. R. R. Tolkien's fantasy world of Middle-earth, Arien was the maiden whom the Valar chose from among the Maiar to guide the vessel of the Sun. In the days of the trees in Valinor, Arien had been the one to tend the tree of Laurelin. It is said that she was mightier than Tilion, the Maia chosen to guide the Moon, because she was a spirit of fire, and able to withstand the heats of Laurelin.

"Too bright were the eyes of Arien for even the Eldar to look on, and leaving Valinor she forsook the form and raiment which like the Valar she had worn there, and she was as a naked flame, terrible in the fullness of her splendor."