Chester is a town in Hampden County, Massachusetts, United States, situated in Western Massachusetts. It is part of the Springfield metropolitan statistical area. The town includes the Chester Factory Village Historic District. The total population was 1,228 in the 2020 census.

The area was opened for settlement in the 1750s as Township No. 9. It was incorporated as Murrayfield by the Massachusetts General Court on October 31, 1765. The town’s name was often confused with that of nearby Myrifield, also spelled “Merryfield” (now Rowe, Massachusetts) so the town petitioned the General Court to change its name to “Fairfield”. The General Court chose the name “Chester” instead and passed the act to change its name on February 21, 1783.

The Western Railroad (later Boston & Albany Railroad) opened to Chester on May 24, 1841. In 1893 the collapse of a railroad bridge in Chester killed 14 people.

Set on the eastern edge of the Berkshires, Chester makes up the northwest corner of Hampden County. It is bordered by Huntington on the east, Worthington and Middlefield on the north, Becket on the west, and Blandford on the south. Chester is 21 miles (34 km) southeast of Pittsfield, 30 miles (48 km) northwest of Springfield, 115 miles (185 km) west of Boston, 60 miles (97 km) southeast of Albany, New York, and 150 miles (240 km) northeast of New York City.

According to the United States Census Bureau, the town has a total area of 37.2 square miles (96.3 km), of which 36.6 square miles (94.8 km²) are land and 0.58 square miles (1.5 km), or 1.56%, are water. It is drained by tributaries of the Westfield River. Many brooks flow into the Westfield throughout Chester. The West Branch of the Westfield flows through the western and southern parts of town and passes through the village of Chester, while the Middle Branch flows through the northern and eastern parts of the town, passing through the villages of North Chester and Dayville. The small village of Chester Center occupies high ground between the two river branches. U.S. Route 20 follows the West Branch from the southeast corner of the town to Chester village, then turns west up the valley of Walker Brook on its way to the town of Becket.

On August 2, 1975, the temperature in Chester rose to 107 °F (42 °C). This remains the hottest temperature ever recorded in the state of Massachusetts, along with a similar reading in New Bedford on the same day. On January 12, 1981, the temperature at Chester fell to −35 °F (−37 °C), the coldest temperature ever recorded in Massachusetts. Thus, Chester is only one of three places in the United States which has recorded both of its state’s extreme temperatures, the others being Millsboro, Delaware, and Warsaw, Missouri.

As of the census of 2000, there were 1,308 people, 500 households, and 360 families residing in the town. The population density was 35.6 inhabitants per square mile (13.7/km²). There were 580 housing units at an average density of 15.8 per square mile (6.1/km). The racial makeup of the town was 98.24% White, 0.15% African American, 0.46% Native American, 0.08% Asian, 0.31% from other races, and 0.76% from two or more races. Hispanic or Latino of any race were 1.30% of the population.