Lake Tåkern is a lake in Östergötland County, Sweden. It is considered one of northern Europe’s foremost bird lakes. It is 12 km (7.5 mi) long and 8 km (5 mi) wide, with an average depth only 0.8 metres (2.6 ft).

The lake lies around 20 km (12.4 mi) west of Mjölby, bordering in the west to Omberg. The whole lake, with the surrounding beaches, has been a nature reserve since 1975. From April to the end of July, it is not open to the public, except for visiting areas and walking routes.