Marlborough is a town in Hartford County, Connecticut, United States. It contains the census-designated place (CDP) of Terramuggus. The town is part of the Capitol Planning Region. The town's population was 6,133 at the 2020 census. Marlborough is a 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. Educationally, RHAM High School, which serves Marlborough, Hebron, and Andover students, is one of the top-ranked regional high schools in the state on the SAT in 2017, and 11th highest-performing school in the state on the test. The town is home to Elmer Theines-Mary Hall elementary school which serves Pre-K through 6th grade. The school scores above state average on standardized testing and student progress.
The earliest inhabitants of present-day Marlborough, prior to the arrival of the English settlers, were the Podunk people, an indig