Question: I wish to use the following sentence as the comment on a form field. I have already come up with a short-form label for the field. This text is meant to explain the field in a bit more detail:

**The country [where] you come from.**

The question is: is this "where" needed there, can be used there (optional) or cannot be used there (error).

As English is not my mother language, sometimes these things come up. Please don't be hard on me.

EDIT: I'm somewhat overwhelmed by the answers and appearing complexity of the issue. Yes, I have an input field and I wish to write a label to it. We all know the basic phrases like "I come from Australia" - "Where do you come from?". Cannot it be turned around in the form like "The country you come from"? 

And if the following would be correct: "The country I live **in**"? Or I may only put the preposition to the end if it's not an independent clause but a subordinate one (terms may not be correct, forgot them): I've returned to the country I live **in**.

Answer: 
**The city from which you came.** 

"From" is a preposition. It's a grammatical error to end a sentence with a preposition.

However, used in the context of an input form, "[City or Country] of Origin" would be more suitable.
The complete form would be `The city from which you come`. As it's a relative clause with the pronoun as its object, you can leave it out. ("contact clause")