What's a word to describe something that is "non-English?"
It seems to me like you already know and decided against this option (given you use it in your post), but I think the right expression is, in fact, non-English films. Or if you want to be even more clear (and are OK with something longer), non-English-language films. Both are used and mean the same thing (films not in the English language).
"Non-English films":
- Best non-English films - IMDb
- 3 Non-English Films That Will Make You Forget You're Reading Subs
- Is it anti-American to like non-English movies? | Scanners | Roger Ebert
"Non-English-language films":
- List of most expensive non-English-language films - Wikipedia
- If You've Seen 40/100 Of These Non-English Language Films, You're A Serious Film Nerd - BuzzFeed
- How to handle non english language films? : radarr - Reddit
Disclaimer
The following attempts to offer solutions that respond to the dilemma described by the OP. None of the solutions below mean "non-English" as requested in the OP's title.
Films made around the world with English subtitles.
If a film is described as having English subtitles, readers/viewers will infer that it is not in English. Alternatively, may I suggest either mother-tongue, one's native language,
Films in mother-tongue with English subtitles
or
Multinational films with English subtitles
International films with ...