In J. R. R. Tolkien's fantasy world of Middle-earth, the Misty Mountains (also known by its Sindarin name of Hithaeglir - misspelled as Hithaiglin on the original Lord of the Rings map - and as the Mountains of Mist) are a long mountain range, running north to south, between Eriador and Anduin and from Carn Dûm in the far north to Methedras in the south.

The Misty Mountains were created by Melkor who wanted to make it difficult for Oromë, who often rode across Middle-Earth hunting, to pass. Their most important peaks are Caradhras, Carn Dûm, Celebdil, Fanuidhol and Methedras. The most important passes are the Gap of Rohan, the High Pass and the Redhorn Pass. Under the Misty Mountains are the former Dwarf realm of Moria and the Orc mines in which Bilbo Baggins stumbles across the One Ring.

Led Zeppelin recorded a song, "Misty Mountain Hop", which seems to have borrowed the name but little else from Tolkien. Several other Led Zeppelin songs contain Tolkien references.

Robert Jordan's fantasy series The Wheel of Time also features a mountain range called the Mountains of Mist.