In Austria we have a page called ANNO were you can look up newspapers from the 17th to the 20th century. http://anno.onb.ac.at Of course it's all in German but maybe there are pages like this for other countrys as well. It would be really cool if everybody could post the ones they know and we create a little collection. Because I doubt there's some kind of international database.

archive.org has so much material if you know what you're looking for. For example, Allan Hume, the british official who collected hindu leaders to make up the first Indian National Congress was also really into birds and published a journal of ornithology called stray feathers. You can find fun stuff like this on that website:

https://archive.org/details/strayfeathersjou101887hume/page/n6

Many libraries have microfilm and microfiche archives of newspapers, periodicals, and journals. The larger libraries would have correspondingly larger collections for viewing, such as the New York Public Library with over 350,000 rolls of microfilm and 3,000,000 microfiche. Your local library may have a small collection of the local newspapers.

The New York State Historic Newspapers website holds copies of newspapers from all over the state, ranging from the eighteenth century to close to the present day.

Gallica has five million French documents, from illuminated manuscripts to fashion magazines.

If you are looking for Texas and/or U.S Southwest related periodicals give the Portal to Texas History a look: https://texashistory.unt.edu/

A lot of great newspapers, among other primary and secondary resources, dating back to before the Texas Revolution. All free.