The Steenwijkerdiep is a roughly 9. 5-kilometer waterway in the Dutch province of Overijssel, forming the canalized lower course of the Steenwijker Aa.

Opened in 1632, it serves as a key link in the network of waterways connecting Steenwijk to the lake district of the Kop van Overijssel and the Friese waterways to the north.

From Steenwijk the canal runs southwest to Wetering, where boaters can continue south toward the Giethoornsche Meer or north through the Weerribben toward Ossenzijl and Friesland.

The waterway sits at a crossroads of popular cruising routes, giving access to Giethoorn, Nationaal Park de Weerribben, and the Beulaker- and Belterwijde lakes.

A visitors' harbour along the Steenwijkerdiep in Steenwijk provides moorings, and a marina (Jachthaven Steenwijkerdiep) on the canal's edge offers berths and boat storage with open views across the surrounding polders.