It is situated mainly on the islands of Usedom and Wolin, but also occupies smaller islands, of which the largest is Karsibor island, once part of Usedom, now separated by a Piast canal dug in the late 19th century to facilitate ship access to Stettin (Szczecin).

Since 1999 Swinoujscie has been a city with the administrative rights of a county (powiat) (Polish: miasto na prawach powiatu), within West Pomeranian Voivodeship. It was previously part of Szczecin Voivodeship (1975-1998). The city lies in the geographic region of Pomerania and had a population of 41,100 in 2006.