Yunxi County (simplified Chinese: 郧西县; traditional Chinese: 鄖西縣; pinyin: Yúnxī Xiàn) is a county in the northwest of Hubei province, China, bordering Shaanxi province to the north and the west. It is under the administration of the prefecture-level city of Shiyan. The county spans a total area of 3,509.6 square kilometres (1,355.1 sq mi), and has a population of 447,482 as of 2010.