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.