Italy: Official name is Alice (pronounced Ah-LEE-che).
Germany: Official name is Monica, or Monika as the Germany variant.
Japan: Official name is Sakura.
America: No official or suggested names by Himaruya. In the Japanese fandom she is referred to as Emily Jones, although some English-speaking have named her Amelia.
England: Both fans and Himaruya alike refer to her character as Igiko in Japan, although that's not really her name. Her official name is Rosa. But she was given the name Alice Kirkland in the Japanese fandom, although the English fandom sometimes calls her Elizabeth or Victoria.
France: No official or suggested names by Himaruya. Her fanon name is Françoise Bonnefoy. Although, some fans call her Marianne or Francine as well.
Russia: Official name is Anya.
China: Official name is Chun-Yan.
Austria: No official or suggested names by Himaruya. Nyosutoria is her Japanese fanon nickname. Anneliese is her Western fanon nickname. Her typically used fanon name, however, is either Sophie or Sophia.
Belarus: No official or suggested names by Himaruya. His fanon name is Nikolai Arlofsky.
Canada: Her official name is Maguerite (Meg for short). Some people refer to her as Maddie, Madeline or Nyonada.
Hungary: No official or suggested names by Himaruya. Fan official name in the Japanese fandom is Daniel Héderváry, though Gary (or Gari) are sometimes used.
Korea: No official or suggested names by Himaruya. Fandom usually simply calls her Fem!Korea. An occasionally used named by the fandom is Im Soo Jin.
Liechtenstein: No official or suggested names by Himaruya. The Japanese fandom calls him either Hr. Noah Stein or sometimes gives him his brother's surname, making him Hr. Noah Zwingli. Hr. is Herr for short, meaning "Mister" in Germany and Scandinavia. Rihi-kun and Stein-kun are his two nicknames.
Switzerland: Her official name is Adelheid (nickname Heidi)
Prussia: Her official name is Julchen (nickname for Julia)
South Italy: Official name is Chiara
Spain: No suggested names by Himaruya. Her two fan-official names in Japan are Isabel Fernandez Carriedo and Carmen Hernandez Carriedo.
Vietnam: No official or suggested names are Himaruya. His fanon name is usually Viet-kun.