What fictional world is the setting for most of J.R.R. Tolkien’s legendarium?

Middle-earth is the fictional world that contains most of J.R.R. Tolkien’s legendarium.

The name appears in Tolkien’s writings as a translation of an older Germanic concept referring to the inhabited world between different cosmic realms. In Tolkien’s mythology, Middle-earth is not another planet; it is a region of Arda, the world created within his broader fictional history.

The Hobbit and The Lord of the Rings are principally set in Middle-earth, as are many stories later collected in The Silmarillion and Unfinished Tales. Important locations include the Shire, Rivendell, Mordor, Gondor, and the Misty Mountains.

Readers sometimes use “Middle-earth” as if it means the entire Tolkien universe. More precisely, it is one major part of Arda, while places such as Valinor belong to other regions of that world. The term is also commonly written with a hyphen: Middle-earth.