While regional definitions vary, the MetroWest Economic Research Center at Framingham State College defines MetroWest as the nine towns of Ashland, Framingham, Holliston, Hopkinton, Natick, Sherborn, Southborough, Sudbury, and Wayland, representing a total population of approximately 184,000. With the exception of Southborough, in Worcester County, the towns of MetroWest are part of Middlesex County.
The 495/MetroWest Corridor Partnership calls the region the "Arc of Innovation" because it is home to many of Massachusetts' largest and fastest growing companies. In addition to the nine towns mentioned above, 23 other municipalities are included in the 495/MetroWest Corridor as defined by the 495/MetroWest Corridor Partnership:
Originally, "MetroWest" was newspaper and real estate agent shorthand for "Framingham-Natick area", but a 1991 article in The Boston Globe showed, by examining the local phonebook, how accepted the term had become in less than 10 years:
In the 1998 edition, there are 88 [listings], from Metro West Christian Academy in Ashland to Metrowest Urology in Natick, including such big names as Metrowest Bank, MetroWest Medical Center and the Metrowest Economic Research Center at Framingham State College. On Beacon Hill, there is a Metrowest Legislative Caucus.
By 2006, the name had gained such widespread acceptance in Massachusetts -- and was so synonymous with prosperous businesses -- that the airport commission in Worcester, a half-hour drive west of MetroWest, suggested changing the name of the city's airport from Worcester Regional Airport to "Worcester-MetroWest-Boston Airport".
The designation "MetroWest" is also used by certain regions west of metropolitan areas in other states such as New Jersey, though the term does not appear to have achieved elsewhere the level of usage it has in Massachusetts.