English: Thyagaraya Nagar, popularly known by its abbreviated form T. Nagar, is a neighbourhood in the city of Chennai, India. T. Nagar was constructed between 1923 and 1925 by the Madras Presidency government of the Raja of Panagal as a part of town planning activities initiated according to the Madras Town Planning Act of 1920. The town was named after Justice Party leader Sir P. Theagaraya Chetty. The streets, parks and localities in the new neighbourhood were named after important officials in the provincial government.

The neighbourhood is considered the biggest shopping district in India by revenue.[1] Though conceived as a residential locality, it is now one of the principal shopping districts of the city. It is mostly famous for its plethora of Saree and gold retailers like Pothys, Nalli Silks and Saravana Stores. The neighbourhood is served by Mambalam railway station of the Chennai Suburban Railway Network. Panagal Park is located at the centre of the neighbourhood connecting Five vein-roads of the neighbourhood: North Usman Road, South Usman Road, G.N. Chetty Road, Thyagaraya Road and Venkatanarayana Road. Unofficially, T. Nagar is the Commercial Capital of the City pushing back Parrys Corner, the centre of the city. Pondy Bazaar serves as the Satellite commercial hub for T. Nagar located around the Thyagaraya Road.

T.Nagar is easily accessible from most parts of the city by bus. The T.Nagar bus terminus off Usman Road is a hub for services operating via the commercial district, including routes to Mylapore, Kodambakkam, Avadi, Nungambakkam, Parrys Corner, Ennore, Manali, Tambaram, Poonamallee, Thiruvanmiyur, Ambattur, Pattabiram, Annanagar and Tiruvallur. There are also routes to various places in neighbouring Kanchipuram and Thiruvallur districts.

Other important bus stops in T.Nagar are Panagal Park, Pondy Bazaar, Power House, and Vani Mahal.