Thiruvallur district occupies an area of 3424 km² and has a population of 2,738,866 (as of 2001). It is bounded on the north by Andhra Pradesh state, on the east by the Bay of Bengal, on the southwest by Chennai district, and on the south by Kanchipuram and Vellore districts.

It is well known for the Sri Vaidya Veera Raghava Swami Temple, which is located in the center of the town. This temple one of the sacred 108 temples for Vaishnavites.