The Engadin or Engadine (Romansh: Engiadina , German: Engadin, Italian: Engadina, French: Engadine; tr: Valley of the Inn people) is a long valley in the eastern Swiss Alps located in the canton of Graubünden in southeast Switzerland. It follows the route of the Inn from its headwaters at Maloja Pass running roughly northeast until the Inn flows into Austria, one hundred kilometers downstream. The Engadine is protected by high mountains on all sides and is famous for its sunny climate, beautiful landscapes, and outdoor activities.
The Romansh toponym Engiadina was first attested as Latin vallis Eniatina in AD 930. A derivation from the reconstructed ethnonym *Eniates (with a Celtic suffix -ates denoting "settlers, inhabitants", as in Licates or Atrebates) has been suggested, with the first part of the ethnonym in turn containing the name of the En (< Aenus (Enus)).
The Engadin valley lies at the centre of the Alpine range and constitutes the upper part of the 300 km-long Inn valley. From the Maloja Pass (1,815 m) to the border to Tyrol (1,000 m) north of Vinadi the valley runs for a length of 100 km, always above 1,000 metres in elevation. The highest mountains of the valley are in the Bernina Range in the upper part.