There are several countries that are referred to using the definite article in English; The Ukraine (losing favor with many speakers), The Philippines, The Maldives,a nd some others.
On many tape measures made by Stanley, the country of manufacture is listed as “The Thailand”; “Made in The Thailand”. I’ve bever seen the country’s name referred to in this manner. Is that a typo, or is Thailand really one of the rare countries that is referred to in the definite article?
Paging Siam Sam. 
I’ve never seen “The Thailand”. Maybe they meant “The Kingdom of Thailand”, which would be correct.
I’d say it’s Thailish.
Strictly a mistake, either a typo or a non-native speaker who did it on purpose without knowing proper usage. Articles are a big mystery to non-native speakers. They see “the US,” “the Philippines,” so I can see where some factory worker would think it’s supposed to be “the Thailand.”
It should have been “Made in Thailand” or “Made in the kingdom of Thailand.”
It’s important to know that your goods were made in the Thailand, and not some cheap knock-off Thailand.
Data point:
The United Nations Development Programme’s Style Manual is very specific about place names (wonder why?). It does not use the article.
(pauses to throw a cheap knock-off at Rysto 
)