Saint Patrick, one of the patron saints of Ireland, has never formally been recognized as a saint by a Pope. The reason no Pope has formally recognized him as a saint is because he has never been canonised by a Pope. The process of canonisation is the one in which a deceased person is included in the canon, or list of recognized saints. Even though Saint Patrick’s name is certainly present in the Canon, no Pope has officially recognized him as a saint. Why would this be the case?
OK, we know this is confusing right now, and we will try our best to make it a little less confusing as we go. By the end it should all make sense. In the modern era, the process of declaring a deceased person a saint is a somewhat complicated process. There are a series of steps to go through in reaching the end result, all of which must be met. They have to be a Holy person, and have performed two miracles, among many other requirements. This however has not always been the case, and a long time ago things were very different.
In the first one thousand years of the Christianity there was no such strict process to canonise a saint. Canonisations were done on a regional level following the death of a holy person. In theory, and devoutly religious person who was deemed to have performed a miracle in the region could have become a saint, without any real impartial examination. This is what happened when Saint Patrick was canonised.