Saint John County (2021 population: 76,558) is located in southern New Brunswick, Canada. The city of Saint John dominates the county. Elsewhere in the county, tourism is focused around the Bay of Fundy.
There are two municipalities within Saint John County (listed by 2016 population):
The county is subdivided by the Territorial Division Act (Section 27) into one city and three parishes (listed by 2016 population):
As a census division in the 2021 Census of Population conducted by Statistics Canada, Saint John County had a population of living in of its total private dwellings, a change of from its 2016 population of . With a land area of , it had a population density of in 2021.
Highways and numbered routes that run through the county, including external routes that start or finish at the county limits: