Karkku is a locality and former municipality in Pirkanmaa region, Finland.

Karkku is located by the lake Rautavesi, about 13 kilometres north of the Sastamala town center.

[2] The village of Karkku was the center of the Medieval Sastamala socken (not to be confused with the modern town of Sastamala), which was one of the 10 original sockens of the historical province of Satakunta.

During the 15th and 16th century, Sastamala was split into several smaller parishes.

Karkku is the birthplace of the politician Hannes Ryömä.