Ile Alatau (Kazakh: Ile Alatauy, Іле Алатауы), also spelt as Trans-Ili Alatau, is a part of the Northern Tian Shan mountain system (ancient Mount Imeon) in Kazakhstan and Kyrgyzstan. It is the northernmost mountain range of Tian Shan, stretching for about 350 km (220 mi) with a maximal elevation of 4,973 m (16,316 ft) (Talgar Peak). The term "Alatau" refers to a kind of mountain characterized by interleaving areas of vegetation, scattered rocks and snows. The range is bounded in the north by the Ili Depression of the Ili River, hence the name.
The former capital of Kazakhstan, Almaty, is located at the foot of the range. The Ile-Alatau National Park is a protected area in the Ile Alatau.