As early as 7,000 BCE, prehistoric people in dugout canoes followed the Sudbury and Assabet Rivers to their headwaters in search of quartzite for tools and weapons.

From 1200 to 1600 CE, seasonal migrations brought Nipmuc Indians to hunt and fish near Cedar Swamp and Lake Hoccomocco.

[3] The early English explorer John Oldham followed these trails through Westborough in 1633, and settlers in search of fertile farmlands followed not long after.

On November 18, 1717, Westborough was incorporated as the hundredth town in Massachusetts, populated by twenty-seven families, including Thomas Rice who had represented Marlborough in the Great and General Court.

Soon large farms were carved out, mills built along the Assabet River and Jackstraw Brook, and taverns flourished.

Westborough's first minister, Reverend Ebenezer Parkman, shepherded the growing town of colonists through the years toward independence from Great Britain.

In 1798, he introduced mass production to the United States at his Whitney Arms Company in New Haven, Connecticut.

The railroad brought a new era to the town industry: over the next century, local factories shipped boots and shoes, straw hats, sleighs, textiles, bicycles, and eventually abrasive products, across the nation.

Westborough dairies supplied cities with milk and local greenhouses shipped out carnations, while the eight orchards found ready markets for their produce.

The latest 5-Year 2018–2023 American Community Survey (ACS) estimated the town's total population at 21,591, residing in 8,065 households.

A major CSX rail freight yard serving the Boston metro area is located near the intersection of the Turnpike and I-495.

The Robert F. Kennedy Children's Action Corps, Inc. operates two juvenile correctional facilities in Westborough on behalf of the Massachusetts Department of Youth Services: Cablecast (Public, educational, and government access (PEG) cable TV channels): The Westborough Public Library was founded in 1857.