The Danish and Norwegian surname Jensen is of patronymic origin, being derived from the personal name Jens, a reduced form of Johannes. This is Denmark’s most frequently occurring surname. The name is first recorded in the New World in 1840 when Peter Jensen emigrated from Denmark to Missouri. Today there are approximately 112,000 bearers of the name Jensen in the United States making it the 245th most popular name. A notable bearer of the name is Ronald Bjorn Jensen the American mathematician born in 1936.