Marlborough is a town in Hartford County, Connecticut, United States. It contains the census-designated place (CDP) of Terramuggus. The town's population was 6,404 at the 2010 census. Marlborough is an upper class suburban and rural community. The local high school is RHAM High School. In 2013, Marlborough ranked third (of 24) in Connecticut Magazine's biannual ranking of Connecticut small towns, median home sale price between $175,000 and $224,999.