The term Middle-earth canon, also called Tolkien's canon, is used for the published writings of J. R. R. Tolkien regarding Middle-earth as a whole. The term is also used in Tolkien fandom to promote, discuss and debate the idea of a consistent fictional canon within a given subset of Tolkien's writings.

Middle-earth is the setting of much of the English writer J. R. R. Tolkien's fantasy. The term is equivalent to the Miðgarðr of Norse mythology and Middangeard in Old English works, including Beowulf. Middle-earth is the human-inhabited world, that is, the central continent of the Earth, in Tolkien's imagined mythological past. Tolkien's most widely read works, The Hobbit and The Lord of the Rings, are set entirely in Middle-earth. "Middle-earth" has also become a short-hand term for Tolkien's legendarium, his large body of fantasy writings, and for the entirety of his fictional world.