Thanh Hóa is the capital of Thanh Hóa Province. The city is situated in the east of the province on the Ma River, about 150 kilometers south of capital Hanoi and 1560 kilometers north of Ho Chi Minh City. Thanh Hoa became one of the most populous cities in North Central Coast after expanding in 2012, with a population of approximately 400,000. Thanh Hoa township was upgraded to Thanh Hoa City in 1994 and has been the historical center of politics, economy, culture, education and entertainment of Thanh Hóa Province.

Thanh Hóa is the northernmost coastal province in the North Central Coast region of Central Vietnam. It borders Sơn La, Hòa Bình, and Ninh Bình to the north, Nghệ An to the south, the Laotian province of Houaphanh to the west with a boundary of over 192 kilometres (119 mi) long, and the South China Sea to the east.