what county is wellesley ma in?
Homefacts City Report. Wellesley is located in Norfolk County, MA. The population is , making Wellesley the 9th largest city in Norfolk County. There are 9 public schools in Wellesley with an average Homefacts rating of A. The total crime rate for Wellesley is very low, and there are 0 registered sex offenders residing in the city.