Koothanallur is a town located in the Tiruvarur district of Tamil Nadu, a state in southern India. It is situated approximately 20 km (12 mi) from the district headquarters of Tiruvarur and roughly 350 km (220 mi) from Chennai, the capital city of the state.
The town holds the distinction of being the third largest municipality town within the Tiruvarur district. It serves as a local urban center in the region.