Anniversaries in December
- 1 December
- 1849 – London and South Western Railway opens line from Datchet to Windsor & Eton Riverside.
- 1904 – Metropolitan Railway opens Neasden Power Station.
- 1913 – Baker Street and Waterloo Railway extends from Edgware Road to Paddington.
- 1968 – Victoria line services commence between Highbury & Islington and Warren Street.
- 2 December
- 1955 – Barnes rail crash kills 13 when two trains collide at Barnes station due to a signalling error.
- 2005 – Docklands Light Railway extends from Canning Town to King George V.
- 3 December
- 1927 – Post Office Railway commences operations.
- 4 December
- 1946 – Central line extends from Liverpool Street to Stratford.
- 1957 – Lewisham rail crash kills 90 when a train runs into another in fog causing a bridge above to collapse.
- 5 December
- 1905 – A collapse of a large section of the glazed arched roof of Charing Cross station during maintenance work kills six.
- 1964 – A fire destroys Bishopsgate goods station.
- 6 December
- There are no anniversaries today
- 7 December
- 1869 – First East London Railway train runs through the Thames Tunnel.
- 1940 – Metropolitan line stopping services end between Finchley Road and Wembley Park.
- 8 December
- There are no anniversaries today
- 9 December
- 1868 – The world's first traffic light is installed near the Houses of Parliament to control traffic from Westminster Bridge. It used gas-lit lanterns on semaphore signal arms and was manually controlled by a police officer. It exploded on 2 January 1869 and was not replaced.
- 1936 – A crash of a KLM passenger plane into buildings shortly after take-off from Croydon Airport kills 15 including Arvid Lindman, former Prime Minister of Sweden, and Juan de la Cierva, inventor of the Autogyro.
- 2011 – Last articulated buses operate in London.
- 10 December
- 1932 – Metropolitan Railway extends from Wembley Park to Stanmore.
- 11 December
- 1844 – A boiler explosion on a goods train from Bricklayers Arms kills the driver and fireman and damages the timber viaduct near New Cross.
- 1984 – A driver of a Metropolitan line train dies when he runs into the rear of another train in fog near Kilburn.
- 2011 – District line services from Earl's Court to Kensington (Olympia) are reduced to weekend operations only.
- 12 December
- 1988 – Clapham Junction rail crash kills 35 when a wiring fault gives an incorrect signal causing a train to collide with a stationary train.
- 13 December
- 1753 – First Hampton Court Bridge over the River Thames opens.
- 2009 – Circle line extends from Edgware Road to Hammersmith, supplementing Hammersmith & City line services.
- 2009 – First domestic High Speed 1 services begin operating from St Pancras.
- 14 December
- 1836 – London Bridge station opens as the London terminus of the London and Greenwich Railway.
- 1920 – A crash of a Handley Page Transport passenger plane at Golders Green after take-off from Cricklewood Aerodrome kills 4.
- 1947 – Central line extends from Leytonstone to Woodford and Newbury Park.
- 15 December
- 1906 – Great Northern, Piccadilly and Brompton Railway opens between Finsbury Park and Hammersmith.
- 1913 – Thomas Sopwith establishes the Sopwith Aviation Company's factory at Canbury Park Road, Kingston to manufacture aircraft.
- 2017 – All-night London Overground services begin.
- 2019 – TfL Rail begins services between Paddington and Reading as the third stage of the Crossrail service implementation.
- 16 December
- 1864 – The final six wagons of a ballast train become detached in Blackheath tunnel between Blackheath and Charlton stations and are run into by an express train killing five platelayers in the wagons and injuring many on the express. Another platelayer and the fireman on the express die later.
- 1977 – Piccadilly line extends from Hatton Cross and Heathrow Central.
- 17 December
- There are no anniversaries today
- 18 December
- 1890 – City and South London Railway opens between Stockwell and King William Street.
- 1890 – London and North Western Railway opens its branch from Harrow & Wealdstone to Stanmore.
- 19 December
- 1973 – Ealing rail crash kills 10 when an express train derails between Ealing Broadway and West Ealing due to an equipment failure.
- 20 December
- 1946 – District line first serves Kensington (Olympia) for exhibitions only.
- 21 December
- 1864 – Ludgate Hill opens as the London terminus of the London, Chatham and Dover Railway.
- 22 December
- 2007 – East London line closes for conversion to mainline operation as part of London Overground.
- 23 December
- 1865 – Metropolitan Railway extends from Farringdon to Moorgate.
- 24 December
- 1838 – London and Greenwich Railway opens line from Deptford to Greenwich.
- 1868 – Metropolitan Railway extends from Gloucester Road to South Kensington.
- 1868 – District Railway opens between South Kensington and Westminster.
- 1924 – A crash of an Imperial Airways passenger plane at Purley shortly after take-off from Croydon Aerodrome kills 8.
- 25 December
- There are no anniversaries today.
- 26 December
- There are no anniversaries today
- 27 December
- There are no anniversaries today
- 28 December
- There are no anniversaries today
- 29 December
- 1905 – Death of Charles Yerkes chairman of the Underground Electric Railways Company of London.
- 30 December
- There are no anniversaries today
- 31 December
- 1906 – Metropolitan Railway services end between Goldhawk Road and Richmond.
- 1945 – Northwood train crash kills 3 when a train runs into another in fog.
- 1964 – Brentford Dock closes.
