The Third Age was the age of Middle-earth, beginning with the first downfall of Sauron and the deaths of Gil-galad and Elendil, and ending with the War of the Ring. With the end of the War came the second and final downfall of Sauron, and the Last Riding of the Keepers of the Rings, in which the greatest of the Eldar still in Middle-earth departed over Sea.

During this Age, the Elves and Dwarves remained in Middle-earth but did little new, while men increased in power and numbers. The Dúnedain kingdoms of Arnor and Gondor prospered at first, but waned as the evils of the Second Age, especially the Nazgûl and Sauron, rose again. In the end, however, the desperate gamble of the Wise to preserve the free-peoples succeeded, and great evil was banished, but at the same time much good and beauty was lost to Middle-earth.

The years of the Third Age were called the Fading Years by the Elves.