Lindon is the land beyond the Ered Luin, the Blue Mountains, in the northwest of Middle-earth in the fictional universe of J. R. R. Tolkien. It is the westernmost land of the continent. The Gulf of Lune divides it into Forlindon (North Lindon) and Harlindon (South Lindon). Mithlond or the Grey Havens stood near the mouth of the River Lhûn at the gulf's eastern end.

Lindon is notable in Tolkien's works in that it serves as a narrative plot device as the final point of transition from the mortal changing world of Middle-earth to the unchanged Arda of the past.

The land Ossiriand, or Land of Seven Rivers, was the most eastern region of Beleriand during the First Age, lying between the Ered Luin and the river Gelion.

The Seven Rivers were, from north to south:

Along the northern shore of the Ascar ran the Dwarf-road to Nogrod. North of Ossiriand lay the land of Thargelion, and south of the river Adurant later lay the Land of the Dead that Live, where Lúthien and Beren lived their second lives.

Ossiriand was a green and forested land, and it was not populated by the Sindar. In the early First Age before the rise of the Moon, a part of the Telerin Elven people called Nandor entered Ossiriand under their leader Denethor, and were given permission by Thingol to settle the lands. After them the land was often renamed Lindon, for The Singers, after the old clan-name of the Telerin which the Nandor still used in their tongue. They became known as the Laiquendi, or Green Elves. After their leader Denethor was killed in an Orc-raid they chose no more leaders, and many of them removed to Doriath.