- Source: Petrus Olai (disambiguation)
Petrus Olai is a latinization of Peder (Per) Olsson (Olsen) or Olofsson, used by a number of early modern Scandinavian authors:
Petrus Olai (Peder Olsen), ca. 1490–ca. 1570, Danish Franciscan friar and historiographer
Petrus Olai Dalekarlus (1601–1680), Swedish pastor and politician
