Question about my heritage? Vincent surname?

My last name is Vincent, and my family is predominantly Irish. My father's parents came from to the Midwestern US from Newfoundland, Canada after living there. My grandfather (on my father's side) was originally Presbyterian and converted to Catholicism. He told me that he and my grandmother Irish and Scotch-Irish. However, I wasn't aware that Vincent was a name that belonged to one of those. Can someone give me the origin the the Vincent surname or explain why I have this name being Irish?