The Kaveri River water dispute is a long-standing conflict between the Indian states of Tamil Nadu and Karnataka over the sharing of waters of the Kaveri River. The Kaveri River is an interstate basin that originates in Karnataka and passes through Tamil Nadu and Pondicherry before draining into the Bay of Bengal. The genesis of this conflict rests in two agreements in 1892 and 1924 between the Madras Presidency and Kingdom of Mysore. The Kaveri river has a 44,000 km2 basin area in Tamil Nadu and a 32,000 km2 basin area in Karnataka. The inflow from Karnataka is 425 TMCft whereas that from Tamil Nadu is 252 TMCft.

The dispute has its roots in historical agreements and differing demands. The 1924 agreement provided that Tamil Nadu would receive 75% of the water, Karnataka, 23%, and Kerala, the rest. However, after state reorganization in 1956, Tamil Nadu received 75% of Kaveri water and expanded its irrigated areas, but the issues persisted. The Cauvery Water Disputes Tribunal (CWDT) was constituted in 1990 to adjudicate the water sharing issue. The tribunals final order was issued in 2007. As per this, 30 tmc (thousand million cubic feet) was allotted to Kerala, 270 tmc to Karnataka, 419 tmc to Tamil Nadu, and 7 tmc to Puducherry.

The dispute has seen several protests in the last decade, with farmers from both states taking to the streets, demanding a "fair share" of the river water. The issue is complex and has been shaped by politics, geography, and hydrology, and has been exacerbated by the climate crisis.