Unfinished Tales of Númenor and Middle-earth is a collection of stories and essays by J. R. R. Tolkien that were never completed during his lifetime, but were edited by his son Christopher Tolkien and published in 1980. Many of the tales within are retold in The Silmarillion, albeit in modified forms; the work also contains a summary of the events of The Lord of the Rings told from a less personal perspective.

The collection received a cautious welcome from scholars and critics. They noted Christopher Tolkien's warning that a good knowledge of the background was needed to gain much from the stories. Others noted that the stories were among the best of Tolkien's writing; Warren Dunn expressed a wish for the whole of the history in such a format. The book, with its commentary, was commercially successful, indicating a market for more of Tolkien's work and leading to the 12-volume The History of Middle-earth.

On "The Quest of Erebor" in Part Three, Christine Barkley comments that the perspective is the knowledgeable Gandalf's, contrasting sharply with the Hobbit Bilbo Baggins's narrower point of view in The Hobbit. Peter Jackson made use of the story to enrich the narrative for his 2013 film The Desolation of Smaug.