Holliston is a New England town in Middlesex County, Massachusetts, United States in the Greater Boston area. The population was 14,996 at the 2020 census. It is located in MetroWest, a Massachusetts region that is west of Boston. Holliston is the only town in Middlesex County that borders both Norfolk and Worcester counties.

At the time of the earliest European settlements, where Holliston exists now was part of the territory of the Awassamog family of Natick (the first Nipmuc praying town), who also held authority over land near Waushakum Pond at Framingham and land near Annamasset at Mendon. In 1701, a large tract of land that included the west half of Holliston, eastern Milford and parts of Hopkinton and Ashland was given to the local Nipmucs in a land exchange with Sherborn.