Matthiessen 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, Mathiesen, Matthissen (UK), Matthisen and Mathissen.
A similar diversity of forms exist for the parallel given name Mathias.
There are several people with the surname Matthiessen: