Chennai formerly known as Madras, is the capital city of Tamil Nadu, the southernmost Indian state. It is the state's primate city both in area and population and is located on the Coromandel Coast of the Bay of Bengal. According to the 2011 Indian census, Chennai is the sixth-most populous city in India and forms the fourth-most populous urban agglomeration. The Greater Chennai Corporation is the civic body responsible for the city; it is the oldest city corporation of India, established in 1688—the second oldest in the world after London.

Street food, as in other areas of India, are popular in Chennai, despite the common belief in India that street food is unhealthy.The Idly Sambhar is a popular dish, which is served as breakfast or dinner. Apart from regular South Indian street food, the city's streets are also filled with several North Indian street food outlets, most of them established by North Indian migrants themselves.Gujarati and Burmese are also available. Street food in Chennai is so popular that a game had developed based on the TV show The Amazing Race where contestants have to follow clues to Street-food spots in the city.

The city is coterminous with Chennai district, which together with the adjoining suburbs constitutes the Chennai Metropolitan Area,[note 1] the 36th-largest urban area in the world by population and one of the largest metropolitan economies of India. As the traditional and de facto gateway of South India, Chennai is among the most-visited Indian cities by foreigners. It was ranked the 43rd most-visited city in the world in 2015 and 36th in 2019.The Quality of Living Survey rates it as India's safest city. Chennai attracts 45 percent of health tourists visiting India, and 30 to 40 percent of domestic health tourists. As such, it is termed "India's health capital". Chennai has the fifth-largest urban economy,and had the third-largest expatriate population in India.

Ranked as a beta-level city in the Global Cities Index, Chennai was dubbed India's best city by India Today in 2014. It was named the "hottest" city (city worth visiting and worth living in for long term) by the BBC in 2015, citing its amalgam of both modern and traditional values. It was the only South Asian city to feature on National Geographic's "Top 10 food cities" in 2015, and ranked ninth on Lonely Planet's best cosmopolitan cities of the world. In October 2017, Chennai was added to the UNESCO Creative Cities Network (UCCN) list for its rich musical tradition. Chennai hosts more than one-third of India's automobile industry, and is a major film production center, home to the Tamil film industry.

With the history of many neighbourhoods of the city such as Mylapore, Triplicane, and Tiruvanmiyur antedating that of the city itself, the architecture of Chennai ranges in a wide chronology. The oldest buildings in the city date from the 7th and 8th centuries CE, which include the Kapaleeshwarar Temple in Mylapore and the Parthasarathy Temple in Triplicane, built in the Dravidian architecture. This architecture includes various styles, such as those of the Pallavas, the Cholas, and the Vijayanagara empires. The associated Agraharam architecture, which consists of traditional row houses surrounding a temple, can still be seen in these areas.