Naessens is a Dutch patronymic surname, "Naes" or "Naas" being short for "Donaas", a Dutch form of Donatian.Naessens at the Meertens Institute database of surnames in the Netherlands.
People Gaston Naessens (1924–?), developer of 714-X claimed treatment Jens Naessens (born 1991), Belgian footballer Jet Naessens (1915–2010), Belgian actress and director Marie-Thérèse Naessens (born 1939), Belgian racing cyclist Willy Naessens (1939–2025), Belgian industrialist
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