琵琶湖（日语：琵琶湖、びわ湖）位于日本滋贺县，为日本最大的湖泊；日本湖沼水质保全特别措置法指定湖泊，也列入湿地公约国际重要湿地名录中。

Lake Biwa(Japanese:琵琶湖,Hepburn:Biwa-ko) is the largest freshwater lake in Japan, located in Shiga Prefecture (west-central Honshu), northeast of the former capital city of Kyoto. Because of its proximity to the ancient capital, references to Lake Biwa appear frequently in Japanese literature, particularly in poetry and in historical accounts of battles.