King's Cross St. Pancras tube stationLondon Underground station serving both King's Cross and St. Pancras stations. It is a main interchange, with platforms on the Victoria, Piccadilly, Northern, Circle, Hammersmith & City, and Metropolitan lines.
- On the Northern Line it is between Euston and Angel, on the Bank branch.
- On the Piccadilly Line it is between Russell Square and Caledonian Road.
- On the Victoria Line it is between Euston and Highbury & Islington.
- On the Circle, Metropolitan and Hammersmith and City lines, it is between Euston Square and Farringdon.
The first "underground" station at King's Cross opened as part of the Metropolitan Railway in 1863, and was rearranged in 1868 and 1926. New platforms for the subsurface lines of the Underground were opened about 400m to the west in 1941; what remains of the old station is now King's Cross Thameslink, though that is soon to become disused.
The Great Northern, Piccadilly & Brompton Railway (Piccadilly Line) platforms opened with the rest of the line in December 1906, while the City & South London Railway (Northern Line) arrived in May 1907. The Victoria line platforms opened on December 1, 1968, three months after the rest of the Victoria line did.
On November 18, 1987 the station was the scene of the devastating King's Cross fire which killed thirty-one people. As a result of the fire, fire safety procedures on the Underground were tightened and smoking banned throughout the entire network.
The underground part of the station is currently undergoing extensive remodelling works to increase throughflow of passengers, expected when the Channel Tunnel Rail Link opens. The main ticket hall is currently closed, and passengers are instead expected to purchase tickets above-ground opposite the W.H. Smiths in front of Kings Cross station.