Tiruvallur district, also spelled as Thiruvallur district, is one of the 38 districts in the Indian state of Tamil Nadu. The fast developing city of Tiruvallur is the district headquarters. The district has a mixture of urban and rural characteristics. The eastern part of Tiruvallur district is dominated by urban characteristics while the Northern part of the district has influence of Andhra culture due to its position. In 2011, the district had a population of 3,728,104 with a sex-ratio of 987 females for every 1,000 males.

Tiruvallur is a Grade I municipality in the Indian state of Tamil Nadu. It is located on the banks of Coovum river about 46 km (29 mi) from downtown Chennai (Madras) and just 5 km from megacity border, in the western part of the Chennai Metropolitan Area (CMA). It is a satellite town of Chennai and is the administrative headquarters of Tiruvallur District. The town is known for the Veeraraghava Swamy Temple, one of the 108 sacred shrines of Vaishnavites. The tank festival is held at a pond near this temple. A Shiva temple near this shrine which is popular among the locals. There is also a 40-foot (12 m) tall Viswaroopa Panchamukha Hanuman temple, where the murti is made of a single green granite stone.