Statistics released by the EU's statistics agency, Eurostat, show that 7.8 percent of foreigners living in Sweden were given citizenship in 2012.
Hungary tops the table, with 12.8 percent of international residents scoring citizenship rights.
Austria comes bottom, with just 0.7 percent of foreigners granted citizenship.
The research shows that across Europe, increasing numbers of people are being granted citizenship rights, which include the chance to vote in and have a passport from the country where they are living.
More than a third of new citizens are under 25.
A quarter are Moroccans, Turks, Indians, Ecuadorians or Iraqis, according to Eurostat's figures.
Previous research has also revealed that Sweden took in almost 20 percent of the EU's asylum seekers in 2013, more than any other country in the union.
Earlier this month, Sweden’s Migration Board said it expected 83,000 asylum seekers to move to the country by the end of the year, 3000 more than it previously predicted.