Maurits Gysseling (Oudenburg, 7 September 1919 – Ghent, 24 November 1997) was an influential Belgian researcher into historical linguistics and paleography. He was especially well known for his editions and studies of old texts relevant to the history of the Dutch language, and also for his very detailed analyses of historical place-names and their probable origins.
Based upon the results of his study of place-names, Gysseling became one of the proponents of the "Nordwestblok" idea that before the 2nd century BCE the language of Gallia Belgica was an Indo-European language that was neither Germanic nor Celtic. According to his conclusions, the northern Belgae then became Germanic-speaking, and never had been fully Celtic-speaking, in the centuries before Rome conquered them.
Major published works include:
At his death his letters and archives were left to the Ghent University, where he had worked, and the Koninklijke Academie voor Nederlandse Taal- en Letterkunde (Royal Academy for Dutch Language and Literature). Uncompleted works in these records include Het Antroponymisch Woordenboek van België, Nederland, Luxemburg, Noord-Frankrijk en West-Duitsland (tot 1226), the Toponymisch Woordenboek van Oost- en Zeeuws-Vlaanderen and a re-working of Julius Pokorny's Indogermanisches Etymologisches Wörterbuch.