Gaochang or Karahoja (Uyghur: قاراھوجا, romanized: Qarahoja, Қарахоҗа; Chinese: 高昌; pinyin: Gāochāng), is the only district and the seat of the oasis city of Turpan, in the Xinjiang Uyghur Autonomous Region, China. Its population was 254,900 at the end of 2003.

According to the municipal government of Turpan, the district is named after the ancient city of Gaochang. It was also proposed that the district be named after Ayding Lake.

The district was created on 12 April 2015 after Turpan was upgraded from a county-level city into a prefecture-level city. The district has the same size and population as the former Turpan county-level city.

Gaochang District is divided into 4 subdistricts, 5 towns, 3 townships and 1 other township-level division.

Gaochang District has a cold-desert climate (Köppen climate classification Bwk). The average annual temperature in Gaochang is 6.5 °C (43.7 °F). The average annual rainfall is 50.8 mm (2.00 in) with July as the wettest month. The temperatures are highest on average in July, at around 22.8 °C (73.0 °F) and lowest in January, at around −11.5 °C (11.3 °F).