Yanggao County is a county under the jurisdiction of Datong City, Shanxi Province. It was named Gaoliu County in the Western Han Dynasty, renamed Baideng County in Jin Dynasty, and renamed its present name in the third year of Yongzheng (AD 1725) in Qing Dynasty. Yanggao is located in the northeast of Shanxi Province, bordering the Inner Mongolia Autonomous Region across the Great Wall in the north, Hunyuan and Guangling in the south, Yunzhou District in the west, and Tianzhen County and Yangyuan in Hebei in the east, with a total area of 1,598.3 square kilometers. According to the seventh census, as of midnight on November 1, 2020, the permanent population of Yanggao County was 191,981.

In 2009, the Gaoliu County ruins were discovered near Liguantun Village in Longquan Town, 1.5 kilometers away from Yanggao County. The Gaoliu site is about 1,000 meters long from east to west and 620 meters wide from north to south, covering an area of 620,000 square meters. It belongs to the cultural relics of the Han Dynasty.

On September 25, 2018, it was awarded the honorary title of "2018 E-commerce into Rural Comprehensive Demonstration County" by the Ministry of Commerce. On April 18, 2019, the People's Government of Shanxi Province approved Yanggao County's withdrawal from the poverty-stricken county.
In 2020, the gross domestic product (GDP) of Yanggao County reached 552.958 million yuan.