Guangdong is a province on the southern coast of People's Republic of China. The province was previously often written with the alternative English name Kwangtung Province. It surpassed Henan and Sichuan to become the most populous province in China in January 2005, registering 79 million permanent residents and 31 million migrants who lived in the province for at least six months of the year. The provincial capital Guangzhou and economic hub Shenzhen are amongst the most populous and important cities in China.

Guangdong faces the South China Sea to the south and has a total of 4,300 km of coastline. Leizhou Peninsula is on the southwestern end of the province. There are a few inactive volcanoes on Leizhou Peninsula. The Pearl River Delta is the convergent point of three upstream rivers: the East River, North River, and West River. The river delta is filled with hundreds of small islands. The province is geographically separated from the north by a few mountain ranges collectively called the Southern Mountain Range. The highest peak in the province is Shikengkong 1,902 meters above sea level.

Guangdong borders Fujian province to the northeast, Jiangxi and Hunan provinces to the north, Guangxi autonomous region to the west, and Hong Kong and Macau Special Administrative Regions to the south. Hainan province is offshore across from the Leizhou Peninsula.

Cities around the Pearl River Delta include Dongguan, Foshan, Guangzhou, Huizhou, Jiangmen, Shenzhen, Shunde, Taishan, Zhongshan and Zhuhai. Other cities in the province include Chaozhou, Chenghai, Kaiping, Nanhai, Shantou, Shaoguan, Xinhui, Zhanjiang, Zhaoqing, Yangjiang and Yunfu.

Guangdong has a humid subtropical climate (tropical in the far south), with short, mild, dry, winters and long, hot, wet summers. Average daily highs in Guangzhou in January and July are 18 °C (64 °F) and 33 °C (91 °F) respectively, although the humidity makes it feel much hotter in summer. Frost is rare on the coast but may happen a few days each winter well inland.