The Twistesee is a reservoir on the Twiste in the county of Waldeck-Frankenberg in North Hesse, Germany.

The Twistesee is located at the northern end of the Langer Wald around 30 km as the crow flies west-northwest of Kassel between Bad Arolsen in the west, Volkmarsen to the northeast and Wolfhagen to the southeast. The reason for its construction was the so-called Henry Flood (Heinrichsflut) on 16/17 July 1965 that caused serious damage and destruction in the catchment areas of the Twiste and Diemel rivers. Near one riverside village, Wetterburg, the Twiste was impounded by a dam to form a very large flood retention basin in order to control the water level.

Among the sights in the vicinity of the Twistesee are:

• Bad Arolsen, the best known destination near the reservoir.
• Neu-Berich, a village with an interesting past, near the lake.
• Landau, somewhat southeast of the reservoir, has an historical old town which is entirely protected, a palace, an historical town church and the Landauer Wasserkunst, an historical water supply system.
• Near Volkhardinghausen, not far south of the reservoir, stands the French Oak (Franzoseneiche).

• Private website on the Twistesee

• Peter Franke, Wolfgang Frey: Talsperren in der Bundesrepublik Deutschland. DNK – DVWK 1987, ISBN 3-926520-00-0

• List of dams in Germany