The Simien Mountains (Amharic: ስሜን ተራራ or Səmen; also spelled Semain, Simeon and Semien), in northern Ethiopia, north east of Gondar in Amhara region, are part of the Ethiopian Highlands. They are a World Heritage Site (since 1978) and include the Simien Mountains National Park.

The mountains consist of plateaus separated by valleys and rising to pinnacles.

The highest Ethiopian mountain is Ras Dejen at 4,550 m with the second highest peak of Kidis Yared at 4,453 m; other notable peaks include Mount Biuat at 4,437 m.