Charlestown is a city in Washington County, RI, and is located in the southern part of the state, near the coast. It is accessible via Route 1 and is in close proximity to cities such as Westerly and Narragansett.. The business climate in Charlestown makes it a strong option for business expansion and relocation projects because of its strategic coastal location, proximity to major highways, and supportive local government.. The city and neighboring areas are home to organizations and companies such as Ocean House, a lu