The town is approximately 19 miles (31 km) southwest of downtown Boston and is bordered by Norfolk, Sherborn, Holliston, Medfield, and Medway.

In 1713, pioneers of Medfield applied for a grant to create a new town and, when approved, named this new land Medway.

This was arguably his most important accomplishment, as the rail system is regarded as the most significant factor in its independence from Medway.

In addition, the railroad system was a major factor in the early promotion of economic growth in the town and the integration of Millis to the larger cities of Dedham, Boston and Cambridge.

The Bay Colony Railroad merges with the present day MBTA Commuter Rail in Needham.

After the publicity on The Today Show, an estimated 6,000 cars traveled to the "Millis Lights" daily during the Christmas season.

[2] The industrial history of Millis is long and varied, beginning with the water power of a small establishment named Hinsdell's mill.

Some of these industries include the Holbrook factories, which included a bell foundry, organ manufactory, and organ pipe manufactory, Clicquot Club, and Herman Shoe Company; the latter two being the most notable industries in the town's history.

Today the prominent employers in the town are Tresca Brothers Sand & Gravel and Roche Bros. Supermarket.

The Herman Shoe Company, a result of several private buyouts, produced large amounts of material, specifically boots and other equipment, during the Spanish–American War.

The company, which distributed the first brand of ginger ale in the United States for about eighty years, was located on Main Street and is the namesake for the village of Clicquot in Millis.

Clicquot Club owned more than 100 factories throughout the United States and sold its beverages internationally.

The clay excavations were turned into bricks that built many large estates and buildings in the immediate area and beyond.

These abandoned pits are home to many species of wildlife and are protected along with the Great Black Swamp.

It is rumored that Nathan Hale and the Marquis de Lafayette also stopped at the tavern to dine.

On February 21, 1676, Native Americans killed 17 Medfield citizens and destroyed half of the town (32 houses, two mills, and many barns).

Immediately after this attack, the Native Americans under King Philip (Metacom) fled to Millis where they held a grand feast.

The next day, on February 22, the Native American forces led an offensive against the Fayerbanke Palisades at Boggestowe Farms, which are in present-day Millis.

According to the United States Census Bureau, the town has a total area of 12.3 square miles (32 km2).