- 31 May
- 1915 – Metropolitan Railway completes "fast lines" between Kilburn and Willesden Green.
- 1934 – A crash of an Air France transport aircraft into a navigation beacon shortly after take-off from Croydon Airport kills 2.
- 1946 – Heathrow Airport opens as London's main Airport.
- 1948 – Central line extends from Newbury Park to Hainault.
- 1956 – The helicopter shuttle service between Waterloo Air Terminal and Heathrow Airport ends.
- 1997 – British Rail closes the Elmers End to Addiscombe Line.
- 2015 – TfL Rail begins services between Liverpool Street and Shenfield as the first stage of the Crossrail service implementation.