Lake Sempach

Lake Sempach viewed from the air

Lake Sempach (German: [Sempachersee] Error: {{Lang}}: text has italic markup (help)) is a lake in the canton of Lucerne in Switzerland. Its area is about 14.5 km² and its maximum depth is 87 meters.

A 50 metre-large island named Gamma Insel is east of Sursee.

It gives the name to the municipality of Sempach.