The Semien Mountains (also spelled Simien and Simen) lie in northern Ethiopia, north east of Gondar. They are a World Heritage Site and include the Semien Mountains National Park. The mountains consist of plateaux separated by valleys and rising to pinnacles. The tallest peak is Ras Dashen (4,543 m); other notable heights include Mounts Biuat (4,437 m) and Abba Yared (4,460 m).

Because of their geological origins the mountains are almost unique, with only South Africa's Drakensberg having been formed in the same manner and thus appearing similar. Notable animals in the mountains include the Walia Ibex, Gelada Baboon, Caracal and a few Ethiopian wolves.

Although the word Semien means "north" in Amharic, according to Richard Pankhurst the ancestral form of the word actually meant "south" in Ge'ez, because the mountains lay to the south of Aksum, which was at the time the center of Ethiopian civilization. But as over the following centuries the center of Ethiopian civilization itself moved to the south, these mountains came to be thought of as lying to the north, and the meaning of the word likewise changed.