10 Nations With Highest Percentage of Immigrants In Saudi Arabia, a third of residents were born elsewhere By Arden Dier, Newser Staff Posted Jul 21, 2016 1:29 PM CDT 48 comments Comments Syrian refugees arrive in Canada on Dec. 9, 2015. (Chris Young/The Canadian Press via AP) (Newser) – The US is a nation of immigrants, but it's not the nation of immigrants. In Priceonomics' rankings of the most populous countries by percentage of foreign-born residents (it excluded the Vatican, for example, which otherwise would've ranked first), America sits at No. 5. The top 10: Saudi Arabia: 32.3% Australia: 28.2% Canada: 21.8% Germany: 14.9% United States: 14.5% United Kingdom: 13.2% Spain: 12.7% France: 12.1% Ukraine: 10.8% Italy: 9.7% Click for the full list of 50 countries, or see the 10 most peaceful countries.