Grobbendonk is a municipality located in the Belgian province of Antwerp. The municipality comprises the towns of Bouwel and Grobbendonk proper. On January 1, 2006, Grobbendonk had a total population of 10,747. The total area is 28.36 km² which gives a population density of 379 inhabitants per km².
The official flag of Grobbendonk was adopted in 1989. In terms of heraldry, the flag is quartered, I and IV argent, three hills vert, a bird sable, II and III gules three fleur-de-lis argent.