Tiruppur or Tirupur ( ), is a city in the Indian state of Tamil Nadu. It is located on the banks of the Noyyal river and is the fourth largest urban agglomeration in Tamil Nadu. It is the administrative capital of Tiruppur district and is administered by the Tiruppur Municipal Corporation which was established in 2008.

The Noyyal River is a small river in Western Tamil Nadu, and a tributary of Kaveri River. It rises from the Vellingiri hills in the Western Ghats in Tamil Nadu, very closer in proximity to Kerala border, and flows through many villages and the cities of Coimbatore, and Tirupur. Then finally, the river drains into the Kaveri River at Noyyal, a village in Karur district named after the river itself. The river's basin is 180 km (110 mi) long and 25 km (16 mi) wide and covers a total area of 3,500 km2 (1,400 sq mi). Cultivated land in the basin amounts to 1,800 km2 (690 sq mi) while the population density is 120 people per km2 (311/mi2) in the countryside, and 1000 people per km2 (2590/mi2) in the cities. The area is known for its scanty rainfall and the development of the Noyyal River Tanks System to hold any overflow from the rains plus the water of the Northeast and Southwest monsoon season was ecologically important. Kausika river, which originates along the northern side of Coimbatore district in the Western Ghats along with its consequent streams, lake and pond systems is an important tributary of the river. The 173 km (107 mi) long tributary of the Kaveri River filled 32 tanks. These interconnecting tanks held the water flowing from the Noyyal.