Arcot (Tamil: ஆற்kadu) is a town and suburb of Vellore city in the state of Tamil Nadu, India. Located on the southern banks of Palar River at 12°54′N 79°20′E / 12.9°N 79.333°E / 12.9; 79.333, the city straddles a highly strategic trade route between Chennai and Bangalore, between the Mysore Ghat and the Javadi Hills - (Javvadhu malai). Its population in 1991 was 45,205; the surrounding area had a population of 114,760.

Its name is commonly believed to have been derived from the Tamil words aaru (River) + kaadu (Forest). However, arkkaTu meant 'a forest of fig trees'. Jainism was flourishing in this part of Tamil Land who were otherwise known as Arugar most probably corrupted form of Arhants or the perfected souls. The word Arugar is found in many ancient literary works and places dominant with arugars were related to them viz Arakonam, Arumbakkam, Aruvur, etc. Not far away from present day Arcot (Anglicized form of Aarkaadu) there is a place called Arungundram. Hence Arcot or Aarkaadu would have derived its name from Arugarkaadu.

Vellore pronounced [veːluːr] ( listen)) is a tier-II city and municipal corporation in the Vellore district of the Indian state of Tamil Nadu. It became a municipal corporation in August 2008. As of 2012^[update], Vellore is the sixth largest city in Tamil Nadu in terms of population, after Chennai, Coimbatore, Madurai, Trichi and Salem.

Vellore is one of the oldest cities in South India, and lies on the banks of the Palar River on the site of Vellore Fort. The city is located between Chennai (145 km), Bangalore (215 km) and the temple towns of Thiruvannamalai and Tirupati. Vellore has many colleges, ancient temples, a renowned hospital (the Christian Medical College & Hospital) and a well-known technical institute (the Vellore Institute of Technology). Vellore is a transit hub for travellers and tourism.

Vellore has a blend of heritage and culture reflecting the ancient Dravidian civilization. It was the seat of the Pallavas, Cholas, Nayak, Marathas, Arcot Nawabs and Bijapur Sultan kingdoms. Vellore was the capital city of the Vijayanagar empire from 1606–1672. The Vellore Fort was described as the best and strongest fortress during the 18th-century Carnatic Wars, and the monuments found in the district give a vivid picture of the evolution of the city through the ages.