The origins of Sealdah Station can be traced back to the mid-19th century when the British colonial administration initiated the construction of railways in India. The station was named after Frederick William Stevens, the then Governor-General of British India, who held the title of Lord Sealdah. Sealdah Station was officially opened to the public on 2 December 1862, as part of the Eastern Bengal Railway network from Calcutta to Kushtia. At the Calcutta end there was a tin-roofed station room. Sealdah railway station had a proper Station Building in 1869,[6][7] designed by Mr Walter Glanville. The present Sealdah-Ranaghat line was a part of the Sealdah-Kushtia line and was subsequently extended to Goalundo Ghat.
Eastern Bengal Railway Company was registered in 1857 to establish railroad connection between Calcutta and Eastern part of undivided Bengal beyond Ganges(Padma). The first section was completed in January 1862 from Calcutta to Champahati. By May 1862 this extended to Port Canning. Ranaghat was connected in September 1862. Initially, the company was known as Eastern Bengal Guaranteed Railway and ran its trains on guaranteed lines. The guaranteed lines were constructed by companies formed in England. In 1862, the station was well established with 4 platforms
The tram terminus was located at Sealdah Station before the year 1978 from where the concept of horse tram carriage started. There was a tram terminus at Sealdah station. Trams departed from here towards Rajabazar, Howrah Station, Calcutta High Court, Dalhousie Square, Park Circus and Dharmatala. The first horse tram service of Kolkata was also started from Sealdah to Armenian Ghat, following the current route 14 & 16 between Lebutala & Dalhousie Square. The Sealdah–Lebutala & Dalhousie Square–Armenian Ghat (later extended to High Court) stretch is now closed. That terminus was demolished in 1978 also with the Sealdah–Lebutala tram track stretched through Boubazar Street for construction of the Sealdah flyover. Now tram services between Rajabazar–Esplanade, Park Circus–Burrabazar and other services pass through Sealdah. Currently, a car parking exists in place of the old tram terminus.
There are three station terminals at Sealdah: "Sealdah North", "Sealdah Main" and "Sealdah South":[citation needed]
The "North" terminal consists of platforms 1 to 5
The "Main" terminal consists of platforms 6 to 14. One more platform is present beside platform no 14 which is used only by goods trains and high capacity parcel vans.
The "South" terminal consists of platforms 15, 16, 17, 18, 19, 20 & 21.
The north and south sections have a separate set of emerging tracks. The north and south sections are connected by two links: Dumdum–Majherhat link (popularly circular rail) and Bidhannagar Road–Park Circus link (extension of circular rail). These two links were constructed to quickly travel between the two sections, avoiding Sealdah.
Sealdah Main is the mail/express terminal for long-distance trains to northern, north-western, north-eastern and eastern India, through Dankuni line and Bandel line. Krishnanagar line is also serving long distance intrastate trains.
The South section, consisting of Sealdah South terminal, acts as the terminal for local trains plying between Kolkata and Budge Budge, Canning, Diamond Harbour and Namkhana.
There is also an EMU carshed at Sealdah (Narkeldanga). Other EMU carsheds are at Barasat and Sonarpur. A diesel shunter loco shed is also situated at adjacent Beliaghata. A rail coach factory is set to come up at Halishahar-Kanchrapara (Bijpur) region in North 24 Parganas.
Before partition in 1947 of India, trains used to run up to present day Bangladesh along Gede line and Bangaon line. Now Gede line is used by Maitree Express up to Dhaka and Bangaon line is used by Bandhan Express up to Khulna.
IRCTC opened the first executive lounge at this station, the first in any of the main stations in the state of West Bengal. In 2019, on the occasion of Bengali New Year, the lounge was opened. It covers around 2,500 sq ft area, and has free Wi-Fi, showers, foods, newspapers, TV, cloak room facilities available. Though on the first floor, it is next to the elevator to make it accessible to wheelchair users.[12][13]
The station has a first class air conditioning waiting room and a resting area with bedding facilities.
Google provides RailWire free high-speed Wi-Fi.
The station also has many IRCTC food court and restaurants including Haldiram, Jan-Ahaar, Mio Amore and Wow Momos.
Amazon India has launched an Amazon kiosk in the non-ticketing zone, where passengers can pick up their parcels.
The station has a large reservation ticketing zone where passengers can book their tickets in advance.