Big Spirit Lake is a natural body of water, approximately 5,684 acres (2,300 ha) in area, in Dickinson County in northwest Iowa in the United States.

Early French traders named it Lac d'Esprit after the Native legends of an evil spirit who dwelled in the lake.

The drainage area of the lake is approximately 22 square miles (57 km²).

[citation needed] Geologically, the lake, like its neighbors, is a glacial pothole, a remnant of the most recent ice age approximately 13,000 years ago.

The Iowa all-time big fish records for freshwater drum and muskellunge were set from catches in the lake.