East Windsor Township is a township in Mercer County, New Jersey, United States. As of the 2010 United States Census, the township's population was 27,190, reflecting an increase of 2,271 (+9.1%) from the 24,919 counted in the 2000 Census, which had in turn increased by 2,566 (+11.5%) from the 22,353 counted in the 1990 Census.