In addition to already existing requirements in the national travel ban to Sweden
The Swedish government decided on 3 February 2021 that foreign nationals will also have to present a negative test result for ongoing COVID-19 infection upon entry into Sweden, regardless of where they are arriving from. The aim is to reduce the risk of spreading the new variants of the COVID-19 virus that have been detected in a number of countries.
Negative COVID-19 test required for entry into Sweden - Government.se
