Were TMNT II and III really never released overseas?
 

I feel like... they had to have, yet every box office fact sheet on those two I've looked at doesn't list any overseas revenue. Were they really just not released in theaters overseas?

Yeah, they were released. Both films were distributed by companies other than New Line. Maybe that's throwing off the numbers you're referencing?

There were a ton of international movie posters, as well.

Pretty damn sure they were, I got my hands on some old Swedish editions of the Archie issues that seems to imply that. Even if they weren't released in theaters, there are still home video releases.

Taking a look at the sheet for the first one, it just states the foreign total and not any individual countries. Maybe the pre-internet era kept such data more secret? As an example, the original Terminator only lists the UK box office. I might check out some more pre-internet statistics.

OK, now I've checked. The original two Terminators, Little Mermaid, Superman I-IV, Batman 2-3, Rambo I-III and Star Wars IV-VI show a very small amount of countries, only shows a foreign total or no foreign data at all while others (such as the Alien movies) does show plenty of countries.

Yeah. 20th Century Fox released them overseas, in fact.

I saw them in theatres.

Correct, which extended to home video releases as well. Here in the UK I saw the third movie in the cinemas. It was the first movie I ever saw in the cinema actually.

Netherlands here, saw all TMNT movies in theaters