Above is a link to download pages 91-97 of the Electronic Website Guide to Worldwide Institutions Measuring Public Opinion, a great country-by-country list of polling organizations that is now a bit old, but it can still help! It gives the web address for each. If it turns out the web address isn't current, you can search in Google by the name of the organization to try to get more current web address.
Because the results of polls often appear in newspaper articles, you can search Factiva, in particular, for the results of polls and also to get the names of polling services. You can then search for them online. It is not easy to do this kind of search, however. Watch the short YouTube video below to see an example of such a search for opinion polls in Ukraine.
Factiva seems to find the most information from other countries in major news sources, in English and in the local language! The example below is full of nitty-gritty details that are of EXTREME importance, so look closely!
If I were searching for recent polling data on Polish public opinion on Covid and vaccinations as reported in English language sources in Poland, I would do the search described below. Note I selected REGION: POLAND and DATE in the last YEAR.
And below is the basic search statement. Copy it but replace the (covid* or vaccine*) section with words describing your topic of interest.
(public near4 opinion or opinion near4 poll*) AND wc>1000 AND (covid* or vaccine*)
These are some major well-known international polls. These are particularly useful if you want to COMPARE countries. The websites listed below all offer some data for free online. Pay attention to the short descriptions!