Gangavalli is probably named after the holy name "ganga" (river swetha) and the flowering plant "valli", which spread over the river flowing across Gangavalli. In the past 18th and 19th centuries it was ruled by Zamindars, the last of whom was reportedly "Chidambara Mudaliyar" who ruled Gangavalli from 1890 until 1920.^{[citation needed]}

As of 2011^[update] India census,^[1] Gangavalli had a population of 12,015. Males 5,907 and females 6,108. Gangavalli has an average literacy rate of 60%, higher than the national average of 59.5%: male literacy is 68%, and female literacy is 51%. In Gangavalli, 11% of the population is under 6 years of age.

Agriculture is main business. Other businesses include automobile, textiles, and milk products.

Sugarcane, paddy, turmeric, maize and cotton are the main crops cultivated in Gangavalli. It is also noted for tapioca (cassava roots), and there are several tapioca-based industries near Attur which manufacture products such as "javvarisi" (sago) for markets all over India.

The city is part of the Gangavalli (state assembly constituency). A. Nallathambi is the MLA from ADMK party elected in 2021.^[2][3]

Gangavalli is located at 11°29′N 78°39′E / 11.48°N 78.65°E / 11.48; 78.65.^[4] It has an average elevation of 292 metres (958 feet).