The Molenbeek (English: Millbrook) is a brook in the Denderstreek, Belgium. The stream has a length of approximately 22 kilometers. The source of the Molenbeek is located in Grotenberge and the delta is in nearby Wichelen. This brook is not to be confused with the 25-km-lomg Molenbeek-Ter Erpenbeek which is also in Erpe-Mere (and Herzele). The 25-km brook is part of the Molenbeek Erpe-Mere drainage basin.
The basin of the Molenbeek is located in the province of East Flanders, and flows through the municipalities of Wichelen (Schellebelle, Serskamp, Wichelen), Lede (Wanzele, Impe, Smetlede, Papegem, Lede, and Oordegem), Erpe-Mere (Erondegem, Vlekkem, Ottergem, Bambrugge, Egem, and Burst) and Herzele (Borsbeke, Herzele, Ressegem, and Hillegem). The south of the basin comprises a small part of the Zottegem municipality (Grotenberge and Leeuwergem). In the west, it crosses the border of the Sint-Lievens-Houtem territory (Vlierzele, Zonnegem, Letterhoutem).
The Molenbeek (millbrook) is part of the Drie Molenbeken drainage basin. The Drie Molenbeken (three millbrooks) are tributaries of the Bovenschelde. The Bovenschelde is a part of the river Scheldt. The basin of the Molenbeek has an area of approximately 5276 hectares, and is located in the basin of the Bovenschelde. The Molenbeek goes through the Bovenschelde near Wichelen.
From its source in Grotenberge to the delta nearby, Wichelen of the Molenbeek has the following tributaries: Valleibeek, Fonteinbeek, Doormansbeek, Kasteelgracht, Hellegat, Smoorbeek, Kokelaarsbeek, Zijpbeek, Trotgracht, Overimpebeek, Beekveldzijp, Wellebeek, and Vijverbeek.
In the municipality of Erpe-Mere, there are three mills on the Molenbeek. One mill is protected by law, while another has been largely demolished, but there are still remains of this mill, and the mill house itself is still intact.
<Gallery> File:Egemmolen Bambrugge Molenhuis.JPG|Mill house of the Egemmolen at Bambrugge File:Egemmolen Bambrugge overblijfselen.JPG|Remains of the Egemmolen at Bambrugge File:Molens Van Sande Bambrugge vooraanzicht.JPG|Front view of the Molens Van Sande at Bambrugge File:Molens Van Sande Bambrugge zijaanzicht.JPG|Side-view of the Molens Van Sande at Bambrugge File:Molens Van Sande Bambrugge beek.JPG|Place where the mill wheel of the Molens Van Sande once was at Bambrugge File:De Watermeulen Ottergem vooraanzicht.JPG|Front view of the De Watermeulen at Ottergem File:De Watermeulen Ottergem achteraanzicht.JPG|Rear view of the De Watermeulen at Ottergem File:De Watermeulen Ottergem rad.JPG|Mill wheel of the De Watermeulen at Ottergem File:De Watermeulen Ottergem binnenwerk.JPG|The De Watermeulen inside at Ottergem </gallery>