Mathiesen is a Danish-Norwegian patronymic surname meaning "son of Mathies" (equivalent of the Biblical Μαθθαιος, cf. English Matthew). Several spelling variants are used, including Matthiesen, Matthiessen, Mathisen, Matthisen. A similar diversity of forms exist for the parallel given name Mathias. There are several people with the surname Mathiesen:
- Árni Mathiesen (b. 1958), Icelandic politician
- Børge Mathiesen (1918–1962), Danish football player
- Charles Mathiesen (1911–1994), Norwegian speed skater
- Christian Pierre Mathiesen (1870–1953), Norwegian politician for the Conservative Party
- Haagen Mathiesen (1759–1842), Norwegian timber merchant, ship-owner and politician.
- Haaken C. Mathiesen (1827–1913), Norwegian landowner and businessperson
- Haaken L. Mathiesen (1858–1930), Norwegian landowner and businessperson
- Hein-Arne Mathiesen (b. 1971), Norwegian ski jumper
- Jørgen Mathiesen (1901–1993), Norwegian landowner and businessperson
- Mattis Mathiesen (b. 1924), Norwegian photographer and film director
- Mihkel Mathiesen (1918–2003), Estonian politician
- Niels Mathiesen (1829–1900), Norwegian politician and merchant
- Pål Mathiesen (b. 1977), Norwegian musician
- Per Mathiesen (1885–1971), Norwegian gymnast
- Thomas Mathiesen (b. 1933), Norwegian sociologist
Matthiesen may refer to:
- Leroy Matthiesen, Roman Catholic Bishop of Amarillo, Texas