Sint-Gillis-Waas is a municipality located in the Belgian province of East Flanders. The municipality comprises the towns of De Klinge, Meerdonk, Sint-Gillis-Waas proper and Sint-Pauwels. On 1 January 2018, Sint-Gillis-Waas had a total population of 19,273. The total area is 54.98 km2 which gives a population density of 357 inhabitants per km2.