Denmark–Norway was a 16th-to-19th-century multi-national and multi-lingual real union consisting of the Kingdom of Denmark, the Kingdom of Norway, the Duchy of Schleswig, and the Duchy of Holstein. The state also claimed sovereignty over three historical peoples: Frisians, Gutes and Wends. Denmark–Norway had several colonies, namely the Danish Gold Coast, the Nicobar Islands, Serampore, Tharangambadi, and the Danish West Indies. The union was also known as the Dano-Norwegian Realm, Twin Realms (Tvillingerigerne) or the Oldenburg Monarchy (Oldenburg-monarkiet).

Danish is a North Germanic language from the Indo-European language family spoken by about six million people, principally in and around Denmark. Communities of Danish speakers are also found in Greenland, the Faroe Islands, and the northern German region of Southern Schleswig, where it has minority language status. Minor Danish-speaking communities are also found in Norway, Sweden, the United States, Canada, Brazil, and Argentina.