Sayreville is a borough located in Middlesex County, New Jersey, within the United States. It is situated in the New York metropolitan area and lies in the heart of the Raritan Valley region. The borough is positioned on the south banks of the Raritan River and also borders the Raritan Bay.
According to the 2020 United States census, Sayreville had a population of 45,345. This figure represents a growth of 6.2% from the 2010 census count of 42,704, which followed an increase from 40,377 in the year 2000.