Did You Know Superman Was French?

No, seriously.

In that panel from a story by Otto Binder (Superman #146, July 1961, reprinted in Showcase Presents Superman vol. 3), Superman gets an honorary citizenship in all the countries of the United Nations - but the Kryptonian Kal-El adds that "my main loyalty will always be to the United States where I grew up!".

The list in the panel includes only the US, France, Australia and Brazil.

That was the 1961 UN member states therefore Superman is also a Soviet (& Ukrainian & Byelorussian) citizen, a member of the United Arab Republic (which was officially dissolved in October 1961) and other countries which do not exist anymore.

But Kal-El is not German since both Germanies were admitted in 1973.

Add. Scans Daily has a story from 1976 where the USSR protests against the American education of the Kryptonian superweapon.