From the Old Norse personal name Rögnvaldr (composed of regin ‘advice, decision’ (also, ‘the gods’) + valdr ‘ruler’). This name was regularly used in the Middle Ages in northern England and Scotland, where Scandinavian influence was strong. It is now widespread throughout the English-speaking world.
French: habitational name from any of the numerous places so called, named with a religious dedication to St. Lawrence. In some instances the suffix St may have been an ironic attachment to the family name Laurent. As a secondary surname, St. Laurent is associated with Charbonnier, Julien, Laurent, Leclerc, and others.