Place from Tolkien's Legendarium The ruins of Osgiliath during the War of the Ring
Name	Osgiliath (Dome of Stars)
Description	Seat of the Kings of Gondor
Constructed by	Isildur and Anárion
Realm(s)	Gondor
Lord	Kings of Gondor
Type	Capital City
Lifespan	S.A. 3429 – circa T.A. 1640

Location of Osgiliath in Middle-earth marked in red

In the fiction of J. R. R. Tolkien, Osgiliath is a city of Middle-earth, the old capital city of Gondor. In Sindarin, the name means Citadel of the Stars.

Founded by Elendil and his sons Isildur and Anárion at the end of the Second Age, Osgiliath straddled the Great River Anduin at a point approximately half way between the cities of Minas Anor to the west and Minas Ithil to the east. While Anor was the chief city of Anárion and Ithil that of Isildur, the brothers had their thrones alongside each other at Osgiliath.

During the first overthrow of the Dark Lord Sauron, Minas Ithil was taken and Isildur was forced to flee down the Anduin and seek Elendil, but Anárion rallied Gondor's forces at Osgiliath and drove the Enemy back to the mountains.

Osgiliath was burned during the Kin-strife, with its palantír being lost in the rebellion. Afterwards, having not fully recovered from the ruinous civil war, it was struck by the Great Plague, causing it to become partially deserted and fall into ruins. As a result King Tarondor moved the capital to Minas Anor in 1640TA. Around the time that Minas Ithil fell to the Ringwraiths and became Minas Morgul, Osgiliath became unsafe and the remaining population was driven out in 2475 when Uruks from Mordor occupied Ithilien and destroyed the Great Bridge of the city. Although the Uruks were driven back by Boromir, son of Denethor I, the city was finally ruined and from then on it became a city of ghosts watched over by a Gondorian garrison.

Osgiliath was the scene of some of the earliest fighting in the War of the Ring. In 3018 skirmishes broke out as the Black Captain tested the strength of Gondor's outer defences, by occupying East Osgiliath and trying to capture the Western half in addition. Boromir, son of Denethor II led a force that managed to destroy its last stone bridge and therefore halted the advance. After Boromir's departure and subsequent death, his younger brother Faramir took command, but the men of Gondor were hard pressed to prevent the enemy from breaking through at Osgiliath and were eventually driven out by the forces of Mordor shortly before the Battle of the Pelennor Fields.

After the destruction of the One Ring and the fall of Sauron, it may be presumed that Osgiliath was rebuilt although it never regained its former glory. Minas Tirith remained the capital of Gondor and King's city.

The name "Osgiliath" is Sindarin for "Dome of Stars", referring to the city's most prominent building, a great dome which once housed the city's palantír. (Osgiliath's palantír was lost in the river, during the Kin-strife in the time of Eldacar, T.A. 1437.)

In Peter Jackson's film of The Two Towers, Faramir takes Frodo, Sam and Gollum to Osgiliath, where they witness a battle. This does not occur in the book.