Southbury City has a diverse population. The city is home to a high percentage of foreign-born residents, with 14.6%. The majority of residents are married and have children. About 59% of households are headed by a married couple, and the remaining share are headed by single people. The city's average household size is 2.41 people.
Southbury has a relatively small number of water and sewer systems, with most residents using wells. This poses a concern for the city's water table. The town's only car wash is required to recycle the water it uses. The city's gas and electric providers are Eversource Energy and Charter Communications.
The United States Census Bureau estimates the population of Southbury City will be 19,619 in 2020. This is lower than the state and national average. The city is the second-most populous place in the greater Southbury region, behind only Naugatuck, which has a 59.0% larger population. However, Southbury City is facing a downward trend as the number of people is declining.
The town's major industries are agriculture and ice cream. It is the second largest city in Connecticut, and is home to the highest percentage of Western Africans.