The Janssens House is a mansion and museum in the Belgian town of Sint-Niklaas . It is owned by the City of SInt-Niklaas.

The eclectic building was commissioned in 1878 by Alfons Janssens , a textile manufacturer and later a politician of the Catholic Party . Pieter Van Kerckhove, who had also drawn up the design for the new town hall of Sint-Niklaas , was the architect. At the beginning of the 20th century, the building was donated to the city. The condition was that it would be used for art and science. The Royal Archaeological Circle of the Land van Waas (KOKW) has set up a museum and a library. 

Renovation of the building started in 2016. The bricks of the outer facade were all repainted red for this. When the interior renovation will also be completed, in 2020, Huis Janssens will have to take over the museum function of the Salons of Fine Arts . Huis Janssens will then form one large museum site together with the Mercator Museum and the SteM Zwijgershoek .

The house has been protected since 2005.