It is headquartered at Chennai and operates across the states of Tamil Nadu, Kerala, Andhra Pradesh and the union territory of Puducherry.

It has the distinction of operating the first railway line in India, which opened for traffic from Redhills to Chindadripettai in Madras on 12 September 1836.

[9] Southern Railway zone covers the states of Tamil Nadu, Kerala, Puducherry and a small portion of Andhra Pradesh.

[9] Andaman and Nicobar will form part of the zone once the proposed new railway line between Port Blair and Diglipur becomes operational.

[11] Freight operations include container traffic from the ports, coal bound to the thermal power stations, oil and petroleum products from refineries, cement and food grains.

Most of the lines inside ports, thermal stations, manufacturing industries and owned by the respective companies and the zone provides a link connecting to its network along with the wagons and locomotives.

[16] Southern Railway operated ticket printing presses at Royapuram, Thiruvananthapuram and Tiruchirappalli, but these have been phased out due to digitization.

[21] The ICF coaches are slowly being replaced by newer LHB rakes which provide better passenger comfort and safety.

Apart from this, it operates various Passenger trains, DEMU, EMU services, Chennai Suburban and the Nilgiri Mountain Railway.