Tricity, or Tri-City is a metropolitan area in northern Poland, consisting of three cities: Gdańsk, Gdynia, and Sopot, as well as minor towns in their vicinity. They are situated adjacent to one another, in a row on the coast of Gdańsk Bay, Baltic Sea, in Eastern or Gdansk Pomerania. The Tricity metropolitan area has a population of over 1 million people.
The name Trójmiasto was used informally or semi-formally only, until 28 March 2007, when the "Tricity Charter" was signed as a declaration of the cities' cooperation.