The station was opened as part of the original route of the Charing Cross, Euston & Hampstead Railway (now the Charing Cross branch of the Northern line) on 22 June 1907. Prior to the station's opening, the name of "Seymour Street" had been proposed. After opening, it was little used, and for many years it was open only on weekdays, and before 1966 Edgware-bound trains passed through without stopping.
China Miéville mentions this station and its long state of disuse during the 1990s in his novel King Rat (1998), also using it as scene of a brutal murder by dismemberment via a passing train. In Christopher Fowler's "Bryant & May" mysteries, the offices of the Peculiar Crimes Unit are above Mornington Crescent tube station. Mornington Crescent is used by Robert Rankin in many of his novels as the home of the Ministry of Serendipity, a fictional agency whose main activity is to ensure the British Empire rules the globe, via dealings with alien activity and suchlike, the top secret nature of the ministry being the main reason why the station was only open on weekdays and closed for "repairs" for much of the 1990s.
Connections: London Buses routes 24, 27, 29, 46, 88, 134, 168, 214, 253, 274 and C2 and night routes N5, N20, N28, N29, N31, N253 and N279 serve the station.