Which province or city is currently the most populous in Vietnam?

Thanh Hoa is the third most populous province in the country, after two centrally-governed cities, and ranks first among all provinces. Specifically, Thanh Hoa has a population of over 3.7 million people. The average population density of Thanh Hoa is 335 people/km2.

According to the Thanh Hoa Information Portal, the province's population is unevenly distributed across administrative units, between the plains and the hilly and mountainous areas. The population is mainly concentrated in cities, towns, and coastal and riverside areas, and sparsely populated in mountainous regions.

Specifically, the population density in Thanh Hoa City is 2,400 people/km2; in Hau Loc, Hoang Hoa, and Quang Xuong districts, it is over 1,100 people/km2. Meanwhile, in mountainous districts such as Muong Lat, Quan Son, and Quan Hoa, the population density is around 40 people/km2.