The MetroWest region is a cluster of towns lying west of Boston and east of Worcester, in the US state of Massachusetts. While regional definitions vary, the MetroWest Economic Research Center at Framingham State College defines MetroWest as the 9 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 9 towns mentioned above, 23 other municipalities are included in the 495/MetroWest Corridor as defined by the 495/MetroWest Corridor Partnership.