大都市带（Megalopolis）是指有众多在地理上较为接近的大都市，且大都市彼此之间有密切的关系的区域。大都市带的概念最早出现在奥斯瓦尔德·斯宾格勒于1918年的著作《The Decline of the West》和刘易斯·芒福德于1938年的著作《The Culture of Cities》，用来指城市过度发展的第一阶段。后来，他被法国地理学家简·戈特曼于1957年再次提出，用来指美国东海岸的大都市区，其自马萨诸赛州的波士顿开始，经过纽约、费城、巴尔的摩，直至华盛顿特区。大都市带在政治、经济和文化方面有比大都市更重要的地位。世界主要的大都市带有美国的波士顿-华盛顿城市带、芝加哥-匹兹堡城市带及日本的首都圈、京阪神地区等。

A megalopolis (sometimes called a megapolis; also megaregion, or supercity) is typically defined as a chain of roughly adjacent metropolitan areas. The term was used by Patrick Geddes in his 1915 book Cities in Evolution, by Oswald Spengler in his 1918 book, The Decline of the West, and Lewis Mumford in his 1938 book, The Culture of Cities, which described it as the first stage in urban overdevelopment and social decline. Later, it was used by Jean Gottmann in 1954, to describe the chain of metropolitan areas along the northeastern seaboard of the U.S. extending from Boston, Massachusetts through New York City, Philadelphia, Baltimore, and ending in Washington, D.C. and Northern Virginia. The latter is sometimes called the "BosWash megalopolis".