Chennai's culture reflects its diverse population. The city is known for its classical dance shows and Hindu temples. Every December, Chennai holds a five weeklong Music Season, which has been described as one of the world's largest cultural events. The Music Season encompasses performances (kutcheries) of traditional Carnatic music by hundreds of artists in and around the city.

Chennai is also known for the classical Indian dance, the Bharatanatyam, which is also the official dance of Tamil Nadu. An important cultural center for Bharatanatyam is Kalakshetra (Sanskrit for "place of the arts"), located on the beach in the south of the city.

Chennai has a vibrant theatre scene, with a large number of Tamil plays being performed. In general, Tamil theatre is divided into the sabha-oriented theatres, which are parodies on political issues or trends supported by slapstick comedy, and the non-sabha oriented theatre, which includes serious plays and historical plays. English theatre is also popular in Chennai. School and college cultural festivals (locally called culfests) play an important role by providing platforms for the city's youth to indulge in art and culture. These culfests attract participants from around India. Some of the larger culfests in the city are Saarang (IIT Madras), Deep Woods (Madras Christian College) and Down Sterling (Loyola).

Chennai is the base for the large Tamil movie industry, dubbed Kollywood after the locality of Kodambakkam where most of the movie studios are located. The industry makes about 300 Tamil movies a year and its film soundtracks dominate the music scene in the city.

Chennai celebrates a number of festivals. Pongal, celebrated in the month of January, is the most important festival of and is celebrated over a period of five days. Tamil New Year's day signifying the beginning of the Tamil calendar usually falls on April 14 and is celebrated widely. Being a cosmopolitan city, almost all major religious festivals like Divali, Eid and Christmas are celebrated here.

The majorities of residents in Chennai are native Tamilians and speak Tamil. English is widely spoken and is used almost exclusively in business, education and other white-collar professions. Tamil spoken in Chennai uses English words liberally, so much so that it is often called Madras bhashai (Tamil for "Madras language"). There is also a sizeable Telugu-speaking minority in the city. Other languages spoken include Malayalam, and Urdu. A regional hub since British times, Chennai has a large number of Marwari traders. Other prominent communities are the Anglo Indian, Bengali, Punjabi and people from Uttar Pradesh and Bihar.