奥涅加湖（俄语：Онежское озеро）是欧洲仅次于拉多加湖的第二大湖。位于俄罗斯西北部，大部分位于**境内，南部在列宁格勒州和沃洛格达州境内。

属冰川构造湖。湖盆从西北向东南延伸，长250千米。最宽处91.6千米，面积9700平方千米。湖面海拔33米。西北和北岸为由花岗岩组成的曲折岩岸，多湖湾；东南和南为平直的沙岸，多湖滩。湖盆南浅北深，平均水深30米，水体积292×10立方米。有1369个湖岛，总面积250平方千米。大多数水量来自舒亚、沃德拉等58条河流。通过运河与白海、波罗的海相连，有重要航运价值。湖内盛产多种鱼类。

Lake Onega (also known as Onego, Russian:Оне́жское о́зеро, tr.Onezhskoe ozero;IPA: [ɐˈnʲɛʂskəɪ ˈozʲɪrə]; Finnish:Ääninen or Äänisjärvi; Karelian:Oniegu or Oniegu-järve; Veps:Änine or Änižjärv) is a lake in the north-west European part of Russia, located on the territory of Republic of Karelia, Leningrad Oblast and Vologda Oblast. It belongs to the basin of the Baltic Sea, Atlantic Ocean, and is the second largest lake in Europe after Lake Ladoga. The lake is fed by about 50 rivers and is drained by the Svir River.