Germany: Ludwig Beilschmidt (Last name isn't canon, but I'm using it because he needs one).
Prussia: Gilbert Beilschmidt
North Italy: Feliciano Vargas
Japan: Kiku Honda (English style, given name before family name)
America: Alfred F. Jones
England: Arthur Kirkland
France: Francis Bonnefoy
Russia: Ivan Braginsky
China: Yao Wang (English style)
Austria: Roderich Edelstein
Belarus: Natalya Arlovskaya
Belgium: Anri (Not official)
Canada: Matthew Williams
Cuba: Carlos Machado (Not official)
Denmark: Simon Densen (Not official)
Egypt: Gupta Muhammad Hassan
Estonia: Edvard von Bock
Finland: Tino Väinämöinen
Greece: Heracles Karpusi
Hong Kong: Jia Long Wang (English style… I think…)
Hungary: Elizabeta Héderváry
Iceland: Emil Steilsson
South Korea: Young Soo Im (English order?)
Latvia: Raivis Galante
Lichtenstein: Sisia Vogel (Not official)
Lithuania: Toris Laurinaitis
Netherlands: Govert (Not official, no semi-canon last name)
Norway: Børre Thomassen
Poland: Leliks Łukasiewicz
Sealand: Peter Kirkland
South Italy: Lovino Vargas
Spain: Antonio Fernández Carriedo
Sweden: Berwald Oxenstierna
Switzerland: Bash Zwingli
Taiwan: Mei Xiao (English arrangement, not official)
Turkey: SadıK Adnan
Ukraine: IrinaChernenko (Not official)