A surname-style form meaning son of Jan or John, with roots ultimately tied to the Hebrew name Yohanan.
Janssen is a patronymic surname of Dutch and Flemish origin, meaning 'son of Jan,' Jan being the Low German and Dutch form of John. John itself descends through Latin Ioannes from the Greek Ioannes and ultimately from the Hebrew Yohanan, meaning 'God is gracious.' Janssen thus carries an extraordinarily long chain of linguistic transmission, from ancient Hebrew piety through Greek scholarship, Latin ecclesiastical tradition, Germanic vernacular, and finally into the naming customs of the Low Countries, where patronymic surnames solidified in the sixteenth and seventeenth centuries.
It is one of the most common surnames in the Netherlands and Belgium, much as Johnson is in English-speaking countries. As a given name, Janssen draws on the well-established tradition of using surnames — especially family surnames — as first names, a practice with strong roots in American and British naming culture. The name is probably most recognizable to global audiences through the Dutch-South African actress Famke Janssen, whose striking screen presence in films and television elevated the name's profile internationally.
There is also the Janssen pharmaceutical company, a Johnson & Johnson division named for its Belgian founder Paul Janssen, which has kept the name current in global public consciousness. Used as a given name, Janssen occupies distinctive territory: clearly Dutch in its origins, carrying the quiet pride of a heritage surname, yet with a sound — those crisp double-consonants and the rising stress — that translates cleanly into English. It suits parents who want a name that honors ancestry while functioning naturally in an anglophone context.