Soyo, also spelled as Soio, is a city and municipality Angolan From the province of Zaire, located in the north of the country, already on the border with Congo-Quinxassa.
According to the 2018 population projections, prepared by National Institute of Statistics, has a population of 258,599 inhabitants and a land area of 5,572 km². It is the only Angolan municipality that is more populous than the capital municipality of its province, surpassing Mabanza Congo.