Extertal is a municipality in the Lippe district of North Rhine-Westphalia, Germany, with c. 11,500 inhabitants (2013).

Extertal is located on the northern edge of the circle in the Teutoburg Nature Reserve, directly adjacent to Lower Saxony. The Exter and Humme rivers flow through the region. The municipality has its headquarters in the Bösingfeld district. Neighbouring cities are Rinteln, Aerzen, Barntrup, Dörentrup and Kalletal.