Schaalsee is a 24 km (9.3 sq mi) lake in Germany. It forms part of the border between Schleswig-Holstein (district Herzogtum Lauenburg) and Mecklenburg-Vorpommern (districts Ludwigslust-Parchim and Nordwestmecklenburg). The town of Zarrentin is located on its southern shores. Other municipalities on the lake are Seedorf, Sterley, Salem, Kittlitz and Kneese.

It was declared a biosphere reserve in 2000 (309 km).

• Schaalsee-Elbe Biosphere Reserve
• Nixdorf, B.; et al. (2004), "Schaalsee", Dokumentation von Zustand und Entwicklung der wichtigsten Seen Deutschlands (in German), Berlin: Umweltbundesamt, p. 71
• Agroforstprojekt am Schaalsee