patron saint

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A saint who is regarded as the intercessor and advocate in heaven for a nation, place, craft, activity, class, or person.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A saint from whom a specific group claims special protection or prayers.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a saint who is considered to be a defender of some group or nation