Boston is the capital and largest city of the Commonwealth of Massachusetts, and is one of the oldest cities in the United States. The largest city in New England, Boston is considered the economic and cultural center of the region and is sometimes regarded as the unofficial "Capital of New England". Boston city proper had a 2008 estimated population of 609,023, making it the twenty-second largest in the country. Boston is also the anchor of a substantially larger metropolitan area called Greater Boston, home to 4.5 million people and the tenth-largest metropolitan area in the country. Greater Boston as a commuting region includes seven Massachusetts counties, all of Rhode Island and parts of New Hampshire; it is home to 7.5 million people, making it the fifth-largest Combined Statistical Area in the United States.

Boston shares many cultural roots with greater New England, including a dialect of the non-rhotic Eastern New England accent known as Boston English, and a regional cuisine with a large emphasis on seafood, salt, and dairy products. Irish Americans are a major influence on Boston's politics and religious institutions. Boston also has its own collection of neologisms known as Boston slang.Bostonians are often considered to have a strong sense of cultural identity, perhaps as a result of its intellectual reputation; much of Boston's culture originates at its universities. The city has a number of ornate theatres, including the Cutler Majestic Theatre, Boston Opera House, Citi Performing Arts Center, the Colonial Theater, and the Orpheum Theatre. Renowned performing-arts organizations include the Boston Symphony Orchestra, Boston Ballet, Boston Early Music Festival, Boston Lyric Opera Company, OperaBoston, and the Handel and Haydn Society (one of the oldest choral companies in the United States). The city is also a major center for contemporary classical music, with a number of performing groups, some of which are associated with the city's conservatories and universities. There are also many major annual events such as First Night, which occurs on New Year's Eve, the annual Boston Arts Festival at Christopher Columbus Waterfront Park, Italian summer feasts in the North End honoring Catholic saints, and several events during the Fourth of July period. These events include the week-long Harborfest festivities and a Boston Pops concert accompanied by fireworks on the banks of the Charles River.

Because of the city's prominent role in the American Revolution, several historic sites relating to that period are preserved as part of the Boston National Historical Park. Many are found along the Freedom Trail, which is marked by a red line of bricks embedded in the ground. The city is also home to several prominent art museums, including the Museum of Fine Arts and the Isabella Stewart Gardner Museum. In December 2006, the Institute of Contemporary Art moved from its Back Bay location to a new contemporary building designed by Diller Scofidio + Renfro located in the Seaport District. The University of Massachusetts campus at Columbia Point houses the John F. Kennedy Library. The Boston Athenaeum (one of the oldest independent libraries in the United States), Boston Children's Museum, Bull & Finch Pub (whose building is known from the television show Cheers), Museum of Science, and the New England Aquarium are within the city.Boston is also one of the birthplaces of the hardcore punk genre of music. Boston musicians have contributed significantly to this music scene over the years (see also Boston hardcore). Boston neighborhoods were home to one of the leading local third wave ska and ska punk scenes in the 1990s, led by bands such as The Mighty Mighty Bosstones and the The Allstonians. The 1980s' hardcore punk-rock compilation This Is Boston, Not L.A. highlights some of the bands that built the genre. Several nightclubs, such as The Channel, Bunnratty's in Allston, and The Rathskeller, were renowned for showcasing both local punk-rock bands and those from farther afield. All of these clubs are now closed. Many were razed or converted during recent gentrification.