图恩湖（德语：Thunersee）是瑞士伯尔尼州阿尔卑斯山区的一个湖泊，得名于其北岸的图恩城。

大雨之后，图恩湖大约2,500 km²的排水区常会发生水灾，这是因为图恩湖的出口阿勒河排水能力有限。

图恩湖的水源来自东南方比它高6米的布里恩茨湖，以及Kander等溪流。图恩湖是冰河时代的产物，原本与布里恩茨湖是一个湖泊，历史地理学家称为Wendelsee。

渔业相当重要，有不少职业渔民。2001年捕获量为53吨。1835年起湖上开行客船，现在共有10艘，由当地铁路运营商BLS股份公司经营。

Lake Thun (German:Thunersee) is an Alpine lake in the Bernese Oberland in Switzerland named after the city of Thun, on its northern shore.

The lake was created after the last glacial period. After the 10th century, it split from Lake Brienz, before which the two lakes were combined, as Wendelsee ("Lake Wendel"). The culminating point of the lake's drainage basin is the Finsteraarhorn at 4,274 metres above sea level.