Are Irish wool sweaters itchy?

It’s very unlikely that you would ever find out.

The majority of sheep in Ireland are meat breeds. Their wool is poor quality, and usually goes into landfill.

Therefore, there is no Irish yarn to make into egg cozies, much less sweaters.

Most of the (very, very tiny amount of) yarn produced in Ireland is made from Australian merino. That’s not scratchy* in the slightest.

There is some (an incredibly tiny, miniscule amount) wool currently spun from Irish sheep, principally Zwartblés but including some other breeds including the rare-breed native Galway Longwool. However, this is usually only spun in fingering weight, for making socks. You can make a sweater out of sock wool, but it will take years and will only be suitable for hot summers.

Quora linky.