Lorentzen is a Norwegian family of Danish ancestry whose members have been notable as shipping magnates and industrialists over several centuries. The industrialist Erling Lorentzen was married to Princess Ragnhild of Norway (known as Princess Ragnhild, Mrs. Lorentzen after her marriage), the eldest daughter of King Olav V of Norway. Lorentzen is a common patronymic in Denmark and Norway, and the family should not be confused with unrelated families with the same name.