According to the United States Census Bureau, the town has a total area of 28.2 square miles (73 km²), of which 27.5 square miles (71 km²) is land and 0.7 square miles (1.8 km²) (2.62%) is water. Bridgewater is 99th out of the 351 communities in the Commonwealth of Massachusetts, and eighth out of the twenty-seven municipalities in Plymouth County in terms of land area. The town is bordered by West Bridgewater to the northwest, East Bridgewater to the northeast, Halifax to the east, Middleborough to the south, and Raynham to the west. Bridgewater is approximately 5 miles south of Brockton, 10 miles northeast of Taunton, and 25 miles south of Boston, of which it is a suburb.

Neighborhoods in Bridgewater include Stanley, Scotland Park, Pratt Town, Paper Mill Village, and South Bridgewater.

Bridgewater lies along the Taunton River, which has several other rivers and brooks which branch off the main waterway. There are also several ponds, the largest of which is Lake Nippenicket along the western edge of the town. There is a state forest, a town forest, several conservation areas and a large portion of the Hockomock Swamp Wildlife Management Area, in the western part of town. Parts of this swamp give rise to the so-called Bridgewater Triangle, a small area of concentrated reports of strange Fortean phenomena, colonial “dark days”, Bigfoot and mysterious black panthers, UFO sightings, and other weird encounters, a phrase coined by Loren Coleman, author of Mysterious America, often compared to the Bermuda Triangle.

As of the census of 2000, there were 25,185 people, 7,526 households, and 5,584 families residing in the town. The population density was 916.2 people per square mile (353.7/km²). There were 7,652 housing units at an average density of 278.4 per square mile (107.5/km²). The racial makeup of the town was 87.28% White, 17.47% People of Color.

There were 7,526 households, out of which 38.6% had children under the age of 18 living with them, 61.5% were married couples living together, 9.5% had a female householder with no husband present, and 25.8% were non-families. 19.6% of all households were made up of individuals, and 7.7% had someone living alone who was 65 years of age or older. The average household size was 2.81 and the average family size was 3.27.

In the town, the population was spread out, with 22.9% under the age of 18, 14.7% from 18 to 24, 32.9% from 25 to 44, 20.9% from 45 to 64, and 8.6% who were 65 years of age or older. The median age was 34 years. For every 100 females, there were 110.7 males. For every 100 females age 18 and over, there were 111.9 males.

The median income for a household in the town was $65,318, and the median income for a family was $73,953. Males had a median income of $48,438 versus $32,383 for females. The per capita income for the town was $23,105. About 1.9% of families and 3.5% of the population were below the poverty line, including 2.6% of those under age 18 and 6.1% of those age 65 or over.

Statistically, Bridgewater is the 71st largest municipality in the Commonwealth by population, and 110th by population density. In the county, Bridgewater ranks third in population and seventh in density.

Bridgewater was formerly governed on the local level by the open town meeting form of government, led by a Board of Selectmen until January 2011. Bridgewater is now led by seven Precinct Councilors, 1 per precinct, and two “at-large councilors”, with an appointed Town Manager, Assessor, Tax Collector, for a total of nine Councilors. Bridgewater is one of fourteen Massachusetts municipalities that have applied for, and been granted, city forms of government but wish to retain “The town of” in their official names. This is from the majority ‘Yes’ vote on Question #1 at the April 24, 2010 annual town election, to change from a five-person, elected Board of Selectmen to a nine-person, elected Town Council, and thus abolishing the Annual Town Meeting, which was held in 2010 after generations. Town facilities are located at the center of town, with the Police Department headquarters being just west of the Square along Mass. Route 104. There are two fire departments in town, one next to the college and the other in the eastern part of town, directly behind the Town Hall. There is one U.S. Post Office branch, located just north of the town center along Mass. Route 18.

The Bridgewater Public Library is just north of the town center, and is a part of the SAILS Library Network.

On the Commonwealth level, Bridgewater is represented in the Massachusetts House of Representatives of the General Court of Massachusetts as a portion of the Eighth Plymouth District, which includes Raynham and a small portion of Easton. In the Massachusetts Senate, the Town is a part of the First Plymouth and Bristol District, which also includes Berkley, Carver, Dighton, Marion, Middleborough, Raynham, Taunton and Wareham. The Town is also patrolled by the Fourth (Middleborough) Barracks of Troop ‘D’ of the Massachusetts State Police.

The Massachusetts Department of Correction operates several correctional facilities in the Bridgewater Correctional Complex in Bridgewater. The prisons in the complex include Bridgewater State Hospital,Massachusetts Alcohol and Substance Abuse Center,Massachusetts Treatment Center, and Old Colony Correctional Center.

On the national level, Bridgewater is a part of Massachusetts’s 8th congressional district, which has been represented in the United States House of Representatives since 2001 by Stephen Lynch, a Democrat. The Commonwealth’s senior member of the United States Senate, elected in 2012, is Elizabeth Warren. Warren defeated incumbent Republican Senator Scott Brown who had won a special election in 2010 to win the seat after the death of Ted Kennedy. Ed Markey became the commonwealth’s junior Senator after he won a special election to the U.S. Senate to succeed John Kerry after his confirmation as United States Secretary of State. The Town also has a Massachusetts National Guard armory along Mass. Route 18.

Bridgewater is the site of the intersection of Interstate 495 and Mass. Route 24, with only a one-mile stretch of the interstate highway running through the southwestern corner of the Town. Just north of this intersection along Mass. Route 24 are two large service areas, both of which have restaurants and a gas station. They are the only two such full service areas along Mass. Route 24, or, for that matter, anywhere along the highways of Southeastern Massachusetts (aside from a stop along U.S. Route 6 in Barnstable; that stop, however, is considered to be off the highway). At the center of town, Mass. Route 18, Mass. Route 28 and Mass. Route 104 meet at the Town Common. Mass. Routes 18 and 28, both north–south routes, are coextensive from this point south to the road’s intersection with U.S. Route 44 in Middleborough. Mass. Route 104 passes from east to west, with ramp access to Mass. Route 24 in the west. A short portion of Mass. Route 106 passes along the town line in the northeast of town; Mass. Route 104 ‘s eastern terminus is at that route, just along the East Bridgewater line.

The Middleborough-Lakeville line of the Massachusetts Bay Transportation Authority (MBTA) commuter rail passes through the Town, with a stop at the southern end of Bridgewater State University’s campus. The stop is just south of the University’s main parking lots at the Southern Campus. There is a small air strip in nearby Taunton, and the nearest national air service can be found at T. F. Green Airport outside Providence and at Logan International Airport in Boston.