Shelton is a city in Mason County, Washington, United States. Shelton is the western most city on the Puget Sound. The population was 8,442 at the 2000 census. In terms of population, the city is ranked 161 out of approximately 500 municipal areas in Washington. Shelton has a unique form of government in the State of Washington. It is the only city in the state which still retains the commission form of government. It is the county seat of Mason County. Shelton apartments for rent comparison page shows most up to date rent information on Shelton apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.