Twin cities are a special case of two cities or urban centres that are founded in close geographic proximity and then grow into each other over time, losing most of their mutual buffer zone. In the United States, "the Twin Cities" usually refers to the Minneapolis-Saint Paul metropolitan area in Minnesota.

Minneapolis–Saint Paul is a major metropolitan area built around the Mississippi, Minnesota and St. Croix rivers. The area is commonly known as the Twin Cities for its two largest cities, Minneapolis and Saint Paul, the city with the highest population in Minnesota and its state capital, respectively. It is a classic example of twin cities in the sense of geographical proximity. Together the two cities anchor the second-largest economic center in the Midwest, behind Chicago.