Lassen is a Danish patronymic surname meaning "son of Lars" (equivalent of Laurentius), and thus a parallel form of the more common surname Larsen. Notable people with the surname include:
Anders Lassen (1920-1945), a Danish recipient of the British Victoria CrossChristian Lassen, a Norwegian-German orientalistClyde Everett Lassen, a United States Navy aviator and Medal of Honor recipientEduard Lassen, a Belgian composerErik Sætter-Lassen (1892–1966), a Danish sport shooterFrederik Lassen, a Danish football playerGeorg Lassen, a German former U-boat captainHans Christian Lassen, a Danish sprint canoerHartvig Lassen (1824–1897), a Norwegian editor and literary historianHenrik Andreas Zetlitz Lassen, a Norwegian politicianInger Lassen (1911–1957), a Danish film actressJean Elisabeth Lassen, a Canadian weightlifterJustin Lassen, an American composer, producer, multi-instrumentalist and remixerLeigh Lassen, an American actressLeo Lassen (1899–1975),an American baseball announcerNiels A. Lassen (1926-1997), a Danish medical researcherPeter Lassen, a Danish-American rancher, prospector and explorerPeter Lassen (footballer), a Danish former football strikerWerner Lassen, a Namibian amateur golferLassen may also refer to Lassen Peak, located in Lassen Volcanic National Park, a national park in the United States.
