Which is Sweden’s largest lake by surface area?

Lake Vänern is Sweden’s largest lake by surface area.

Vänern covers about 5,650 square kilometres in southwestern Sweden, making it the largest lake in Sweden and the European Union. It is divided into broad eastern and western basins by several islands and peninsulas, giving it the appearance of an inland sea.

The lake drains through the Göta älv, Sweden’s largest river by water flow, toward the Kattegat. Its outlet also connects the lake to the Göta Canal system, which links Sweden’s interior waterways with the Baltic Sea.

Lake Vättern is Sweden’s second-largest lake, so it is the most likely alternative in this question. Vänern is also notable for its deep water, extensive shoreline, commercial fishing, and important wetland habitats around its margins.