Is ITF (International Taekwondo Federation) from North or South Korea?

Both. And neither. And South. Taekwondo (in general) was started before Korea split into north and south. Choi was born in what is now known as North Korea, and there developed much of what he eventually systemitized as taekwondo. But in 1966, ITF (the federation, not the style) was established in not only South Korea, but other nations as well.

What's complicating your question is that there are three ITF's right now. One's headed in Austria; another in Canada; another in the US. Each claim to be the "official" ITF. The one headed in Canada can trace its lineage to South Korea, but I can't source the others' lineages, but I'm guessing South Korea. Either way, South would seem to answer your question.

So if I had to take a stab at your question, I would say the organization was founded in South Korea, but the style was founded in North Korea, although the style was based on a fighting system that was part of both North and South.

South

South

south

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