Oh, Kermit wasn't just on The Muppet Show; he was on Sesame Street too, with dozens of local language adaptations. Though it's not always popular in other countries as it is in the USA, it has been a worldwide phenomenon for decades. It puts Kermit is in the same league as Mickey Mouse. I wouldn't be surprised if the majority of people worldwide recognize him, certainly a large majority in the west.

The Muppet Show was actually shot in the UK at Elstree Studios, produced by Lew Grade at ATV. It was syndicated globally, including to the US, but it was not actually an American show.

Everyone in Belgium above a certain age (I was born in 1974) knows it, and I bet half of them could at least name 5 characters.

Update: I was once on a client mission in Rochester, NY, and when I told the people there that we are deluged with/very knowledgeable of American culture they were very surprised (which in turn surprised me very much).

It's tangential, but the Muppet Show was also shown in the 80s in Eastern Europe. I can only assume that it was a packaged deal of some sort, e.g. that licensing it and showing on state TV (there was no other at the time) was a condition for getting a loan or being allowed to sell local produce to the US?

Reruns of It & Sesame Street was broadcast on the Public TV Channel, in the early '00s. In the Anglophone African country I was currently residing in at the time.

I grew up with it in Germany, dubbed of course. Late 70s.

The muppet show was huge in the UK in the late 70s/early 80s.

Yes, to the extent that “muppet” is now common British English slang for a foolish person - e.g. “some muppet has parked badly and blocked the pavement again”.

We had sesame street in Holland and it was broadcast way into the 90s. But the muppet show too, yes!

Well known in Italy in the '80s.

Wait, what? The Muppets was a failure during pilots in the US and only became a worldwide success after it was bought by ATV in the UK - the Muppet Show was produced at Elstree studios in the UK...