Main Street is a metonym used to denote a primary retail street of a village, town or small city in many parts of the world. It is usually a focal point for shops and retailers in the central business district, and is most often used in reference to retailing, socializing, and the place to go to find "common" concerns.

The term is commonly used in Ireland, Scotland, the United States, and Canada, and less often in Australia and New Zealand. In the non-Scottish regions of the United Kingdom, the common description is High Street, though "Fore Street" or "Front Street" is commonplace in some parts. In Jamaica the term is Front Street. In the 1950s awareness about the 'main street' as a concept of its own importance emerged in the urban studies field, attaining the attention in the theoretical discussions of postmodern urban design, neo-traditional planning and meta-urbanism.

In many places, the street name for such a street is actually "Main Street", though even where it isn't the actual name, "main street" is still used to describe the main thoroughfare of the central business district. The "Main Street of America" branding was used to promote U.S. Route 66 in its heyday.

In the general sense, the term "Main Street" refers to a place of small-town traditional values, usually in contrast to big-city modernity. Social realists from 1870 to 1930 used the name as a symbol of stifling conformity. Sherwood Anderson, for example, wrote Winesburg, Ohio: A Group of Tales of Ohio Small Town Life in 1919. The best-selling 1920 novel Main Street was a critique of small-town life by the American writer Sinclair Lewis. The locale was "Gopher Prairie," presented as an 'ideal type' of the Midwestern town, and the heroine, Carol Kennicott, was a more urbane, 'ideal-typical' Progressive.

In North American media of later decades, "Main Street" represents the interests of everyday people and small business owners, in contrast with "Wall Street" (in the United States) or "Bay Street" (in Canada), symbolizing the interests of large national corporations. Thus, in the 1949 movie adaptation of On The Town, the song "When You Walk Down Main Street With Me" refers to small-town values and social life. Main Street Republicans, for example, see themselves as supporting those values as against urbane or "Wall Street" tendencies.

"Main Street" is part of the iconography of American life. For example, the Army and Air Force Exchange Service, the outfit that operates the PX and BX stores on military bases, chose the name "Main Street USA" for its food courts.

Main Street was a popular term during the economic crises in 2008 and 2009: the proposed bailout of U.S. financial system, the 2008 US presidential campaign, and debates. One widely reviewed book was Bailout: An Inside Account of How Washington Abandoned Main Street While Rescuing Wall Street (2012) by Neil Barofsky.

In small towns across the United States, Main Street is not only the major road running through town but the site of all street life, a place where townspeople hang out and watch the annual parades go by. A slang term popularized in the early 20th century, "main drag", is also used to refer to a town's main street.