This is a fully up to date listing of all nineteen languages that Rosemary Sutcliff‘s The Eagle of the Ninth has been published in, in addition to the OUP editions in English. (This listing is from OUP)

English (UK hardback special edition) – Folio Society
English (audiobook – straight reading) – Naxos Audio Books
English (audio – dramatisation) – BBC/AudioGo
English (India) – Penguin India
English (USA) – Square Fish (an imprint of Farrar, Straus and Giroux).

Brazilian Portuguese – Editora Record
Czech – BB Art
Danish – P. Haase & Sons (out of print)
Dutch– Leopold
German – Verlag Freies Geistesleben
Spanish – Plataforma Editorial
French – Gallimard Jeunesse
Greek – Aiora Press
Hungarian – Alexandra Konyveshaz Kft.
Italian – Arnoldo Mondadori Editore
Japanese – Iwanami (out of print)
Korean – Sigongsa
Polish – Wydawnictwo Telbit
Portuguese – Gradiva Publicacoes
Romanian – Editura Litera International
Russian – Azbooka-Atticus
Serbian – Laguna
Swedish – Forlaget Barnstenen (out of print)
Thai – NanMee Books
Turkish – Ithaki Publishing

(I am in the process of tracking down all the websites for the publishers/foreign editions: all help welcome. Post links at comments please!)