I'm writing a novel, my first ever, and I hope to finally finish the story and get it published. I live in Mexico, but I am writing in English...could I get the book published here, or would I have to approach a publishing company in an English-speaking country? I'm thinking maybe I can do it here because I live in Cancún and everyone here speaks English...however, what if it weren't English? What if I wanted to publish a novel in, say, Romanian, or any other "uncommon" language?
Typically, it's difficult to publish in one country using the language of another. Even in the U.S., where there is an ever-growing increase in Spanish-speaking persons, it's difficult to find a publisher for Spanish language books.
If you live in Mexico, reach out to U.S. (or even Canadian) publishing houses with your manuscript. You're more likely to get a bite. Then find an agent that can get it translated and published in Mexico in Spanish.
As I am not in mexico, I will look at this from a slightly more abstract position.
First to note In my hometown I only know of one publisher, but my dad retired from that after publishing only one book. Chances are that you will not find a publisher in your home town. Most of the ones I know of are based in New York.
Let's try another question, what are the most influential publishers where you live? the way to find out this is to just go to a bookstore, or library and find out who published the books that are locally available.
But what about the language issue? Well, in your case I would wander over to the english section of the bookstore/library. It gets harder if you can't buy books in the chosen language locally.
Yes, it is possible to get an English language book published in Mexico or any non-native language book published in foreign countries. I've listed two ways you could go below.
Find yourself a literary agent. A literary agent will handle all the work for you in reaching out to publishers and negotiating international rights. I did some googling and found this http://www.writersdigest.com/editor-blogs/guide-to-literary-agents/literary-fiction-agents but I'd suggest reaching out to some local writers groups in your area and see if you can find any connections through them or reading up on industry news through sources like http://www.publishersweekly.com/ and see if you can find new agents that are accepting submissions.
Submit your work directly to publishing houses, specifically ones that have Spanish language divisions. This is probably not going to be as successful as going through an agent as editors tend to prefer to deal with authors who have agents.