Guiyang is the capital of Guizhou province in the People's Republic of China. It is centrally located within the province, on the eastern part of the Yunnan–Guizhou Plateau, and sits on the north bank of the Nanming River, a tributary of the Wu River. The city is situated at an elevation of approximately 1,100 meters (3,600 ft) and covers an area of 8,034 square kilometers (3,102 sq mi). According to the 2020 census, Guiyang had a total population of 5,987,018, with 4,506,134 lived in its six urban districts.

Guiyang has a humid subtropical climate and is surrounded by mountains and forests. The area has been inhabited since at least the Spring and Autumn period and officially became the provincial capital in 1413, during the Ming dynasty. The city is home to a significant Miao and Bouyei ethnic minority population.

Guiyang has a diversified economy, historically known for aluminum production, phosphate mining, and optical instrument manufacturing. Following economic reforms, the service sector now contributes the majority of the city's economic output. Since 2015, targeted developments in big data have helped Guiyang rapidly emerge as a local innovation hub.

As of 2024, Guiyang is ranked among the top 200 science cities globally based on scientific research outputs, as tracked by the Nature Index. The city is also home to Guizhou University, a national research university under the Project 211 and designated for the Double First-Class Construction in certain disciplines.

The valley approximating present-day Guiyang has been inhabited since the Spring and Autumn period. Guiyang was a 7th-century military outpost under the Sui and Tang, when the area around it was known as Juzhou (矩州). It grew into a city named Shunyuan (順元) under the Mongolian Yuan dynasty sometime between their 1279 southwestern campaigns and 1283. By the time Guizhou became a full province in 1413, its capital at Guiyang was also known as Guizhou. It became a prefectural seat under the Ming and Qing. Guiyang grew rapidly during the development of the southwest that occurred after the Japanese invasion of China during World War II. It has also grown rapidly since Deng Xiaoping's economic reforms reached it in the 1990s.

Guiyang has been designated an ecological civilization pilot city.

The city's heart is around the Dashizi (大十字), a "big cross", and Penshuichi (喷水池, literally "Fountain Pool"), a traffic intersection, in the center of which there was a large fountain until early 2010, when it was paved over for better traffic.

Guiyang has a four-season, monsoon-influenced humid subtropical climate (Köppen: Cwa), tempered by its low latitude and high elevation. It has cool winters and moderate-temperature summers; the majority of the year's 1,149 millimetres (45.2 in) of precipitation occurs from May to July. The monthly 24-hour average temperature ranges from 4.6 °C (40.3 °F) in January to 23.8 °C (74.8 °F) in July, while the annual mean is 15.2 °C (59.4 °F). Rain is common throughout the year, with occasional flurries in winter. With monthly possible sunshine ranging from 11% in January to 43% in August, the city receives only 1150 hours of sunshine, making it one of China's least sunny major cities. Average monthly relative humidity is consistently above 75% throughout the year. The moderate temperature together with other factors including air quality, wind speed, etc. made Guiyang to be ranked No.2 in the "Top 10 Summer Capitals of China". Extremes since 1951 have ranged from −7.8 °C (18 °F) (unofficial record of −9.5 °C (15 °F)) was set in January 1925) to 37.5 °C (100 °F).