I'm looking for a single word for 'immigrant' here, that specifically refers to people from a different part of the same country.
"As the capital city, X has a very large immigrant population".
I feel that immigrant in this sentence could be understood to mean immigrants from outside the country.
Best Answer
I have heard the word "transplant" used to describe people who are living in a place or city that they did not grow up in.
From Oxford Dictionaries Online: