Public transport is provided by the Kolkata suburban railway, the Kolkata Metro, trams and buses. The suburban network is extensive and extends into the distant suburbs.
The Kolkata Metro, run by the Indian Railways, is the oldest underground system in India since 1984. It runs parallel to the River Hooghly and spans the north-south length of the city covering a distance of 22.3 km. Buses are the preferred mode of transport and are run by both government agencies and private operators. Kolkata is India's only city to have a tram network, operated by Calcutta Tramways Company. The slow-moving tram services are restricted to certain areas of the city. Water-logging due to heavy rains during the monsoon sometimes interrupts the public transport.
Hired forms of mechanised transport include the yellow metered taxis, while auto rickshaws ply in specific routes. Almost all the taxis in Kolkata are Ambassadors. This is unlike most other cities where Tata Indicas or Fiats are more common. In some areas of the city, cycle rickshaws and hand-pulled rickshaws are also patronised by the public for short distances. Private owned vehicles are less in number and usage compared to other major cities due to the abundance in both variety and number of public vehicles. However, the city witnessed a steady increase in the number of registered vehicles; 2002 data showed an increase of 44% over a period of seven years. The road space (matched with population density) in the city is only 6%, compared to 23% in Delhi and 17% in Mumbai, creating major traffic problems. Kolkata Metro Railway and a number of new roads and flyovers have decongested the traffic to some extent.

Kolkata has three major long distance railway stations at Howrah, Kolkata (Chitpur) and Sealdah. A third station named Kolkata has been launched at Chitpur in early 2006. The city is the headquarters of two divisions of the Indian Railways - Eastern Railway and South Eastern Railway.
The Netaji Subhash Chandra Bose International Airport at Dum Dum to the north of the city, operates both domestic and international flights. The airport is presently being upgraded to accommodate increased air traffic. Kolkata is also a major river port of eastern India. The Kolkata Port Trust manages both the Kolkata and Haldia docks. There are passenger services to Port Blair in the Andaman and Nicobar Islands and cargo ship service to various ports in India and abroad, operated by the Shipping Corporation of India. There are ferry services as well, connecting Kolkata with its twin city of Howrah.