Templiner See (German pronunciation: [tɛmˈpliːnɐ zeː] ⓘ) is a lake in the state of Brandenburg, Germany.

The navigable River Havel flows through the lake, entering it at its northern end adjacent to central Potsdam, and leaving it at its southern end via a short channel to the Schwielowsee between Caputh and Geltow.

At about its midpoint, the lake is crossed by the Berlin outer ring railway, using an embankment and bridge.

This was built in the 1950s, to bypass West Berlin during the division of Germany.

From 1929 to 1932 Albert Einstein and his wife Elsa, then living in Berlin, had a summer house by the lake in Caputh.