This article is about events from the year 1557 in Sweden

• Monarch – Gustav I

• 2 April - Treaty of Novgorod (1557)
• - The Duchy of Prince John is expanded.
• 7 September - Duke Magnus is granted a Duchy.
• - Crown Prince Eric is granted Kalmar as a fief and is installed there as governor.
• - Gustav Vasa writes his testimony. The son Magnus receives parts of Götalandskapen, Närke, Småland and all of Dalsland as a hereditary duchy.

• Date unknown - Olaus Martini, archbishop (died 1609)

• 1 August - Olaus Magnus, writer and ecclesiastic (born 1490)
• 1 April - Mikael Agricola, Protestant reformer of Finland (born 1510)