The newest edition of the annual English Proficiency Index (EPI) from global language training company Education First (EF) ranked Norway third out of 100 countries that don't have English as a national language.
At the same time Sweden lost its leading position to The Netherlands.
Norway has been climbing steadily from fifth place in 2014, while Sweden this year received its worst score – 68.74 this year – in more than five years.
Malin Ankarberg, EF's Sweden director, said that perhaps the result indicated that Swedes were becoming somewhat complacent about their level of English, which has been at a high level for years.
But she also said one year of a slightly worse score than normal was not a major concern.
"What we're seeing is a small step back, but perhaps it is needed to make the public aware of the fact that we can do better," she told Swedish news agency TT.
The Nordic countries still feature heavily in the list of the best English speakers, with Denmark this year taking fourth place and Finland seventh, but the report said that other countries were catching up.
"The countries with the highest English proficiency in Europe are clustered in Scandinavia, but the number of very high proficiency countries across the region has grown every year since 2017," the report's authors wrote.