Jenssen is a Norwegian patronymic surname meaning "son of Jens". The prefix "Jens-" is a Danish and Frisian derivative of Johannes. There are alternate spellings, including the Danish Jensen, the English language Jenson, and the Belgian/Dutch language Janson. Jenssen is uncommon as a given name. People with the name Jenssen include:

• Amanda Jenssen (born 1988), Swedish singer
• Elois Jenssen (1922–2004), American film and television costume designer
• Geir Jenssen, Norwegian musician best known under the recording name Biosphere
• Hans Jørgen Darre-Jenssen (1864–1950), Norwegian politician
• Hans Wiers-Jenssen (1866–1925), Norwegian novelist
• Jens Martin Arctander Jenssen (1885–1968), Norwegian politician
• Jens Peter Book-Jenssen (1910–1999), Norwegian singer
• Johan Henrik Wiers-Jenssen (1897–1951), Norwegian newspaper columnist
• Lauritz Jenssen (1837–1899), Norwegian businessperson and politician
• Lauritz Dorenfeldt Jenssen (1801–1859), Norwegian businessperson
• Leif Jenssen, Norwegian weightlifter
• Lene Jenssen, Norwegian swimmer
• Matz Jenssen (1760–1813), Norwegian businessperson
• Ruben Yttergård Jenssen, Norwegian footballer
• Worm Hirsch Darre-Jenssen (1870–1945), Norwegian politician