Were the Oz books ever published in countries outside of the United States?
Most certainly. Over the decades there have been numerous Canadian and British editions of the Baum Oz books, and The Wizard of Oz is first known to have been translated into another language, French, in 1932. The Wizard of Oz, other Oz books, and a few of Baum’s non-Oz books have now been translated into a number of different languages, and published in many editions. Even some of the books by other Oz authors are starting to show up in translations around the world. Many of the earliest books published abroad were not translations, but retellings of the story from The Movie.