Columbia is a census-designated place and planned community in Howard County, Maryland, United States. It is a suburb of Baltimore and, to a lesser degree, Washington, DC. It began with the idea that a city could enhance its residents' quality of life. Creator and developer James W. Rouse saw the new community in terms of human values, not just in terms of economics and engineering. Opened in 1967, Columbia was designed to not only eliminate the inconveniences of then-current subdivision design, but also eliminate racial, religious, and income segregation.

Today, Columbia has a population of about 94,600 (making it the largest unincorporated community in Maryland). By the early 2000s, the town had acquired many of the characteristics of other contemporary U.S. suburbs, such as increasingly large private homes on large parcels and "big-box" retail stores accessible mostly by automobile. Nevertheless, Rouse's ethos remains a strong influence upon the physical and political development of Columbia.