A patron saint, patroness saint, patron hallow or heavenly protector is a saint who in Roman Catholicism, Anglicanism, Eastern Orthodoxy, or particular branches of Islam, is regarded as the heavenly advocate of a nation, place, craft, activity, class, clan, family or person. Catholics believe that patron saints, having already transcended to the metaphysical, are able to intercede effectively for the needs of their special charges. 

Historically, a similar practice has also occurred in many Islamic lands. Although Islam has no codified doctrine of patronage on the part of saints, it has nevertheless been an important part of both Sunni and Shia Islamic tradition that particularly important classical saints have served as the heavenly advocates for specific Muslim empires, nations, cities, towns, and villages. With regard to the sheer omnipresence of this belief, the late Martin Lings wrote: "There is scarcely a region in the empire of Islam which has not a Sufi for its Patron Saint." As the veneration accorded saints often develops purely organically in Islamic climates, in a manner different to Catholic and Eastern Orthodox Christianity, "patron saints" are often recognized through popular acclaim rather than through official declaration. Traditionally, it has been understood that the patron saint of a particular place prays for that place's wellbeing and for the health and happiness of all who live therein. The veneration of patron saints has lessened since the eighteenth-century in certain parts of the Islamic world, due to the growing influence in those of areas of latter-day "reformation" movements like Salafism and Wahhabism, which shun the veneration of saints in general.
Where do Catholics believe saints have transcended to?
Catholics believe that patron saints, having already transcended to the metaphysical