John Leonard King, Baron King of Wartnaby (29 August 1917 – 12 July 2005) was a British businessman, who was noted for leading British Airways from an inefficient, nationalised company to one of the most successful airlines of recent times. This success was a flagship of Margaret Thatcher's privatisation programme. He was also directly involved with the "dirty tricks" campaign waged by British Airways, against Virgin Atlantic.
King was born in Brentford, West London. His father Albert had fought in the First World War, and later worked as a postman; his Irish mother Kathleen worked as a seamstress. He was the second of four children. He was reared on a small property attached to a public house in Dunsfold, Surrey. He left school in 1929 at the age of 12 without qualifications and started work in a local factory which produced vacuum cleaners, where his work included machining clamping stays, earning him the nickname "Clamping Stay King". His next job was with local businessman Arthur Sykes, as a car salesman (with duties including re-possessing cars from people who had failed to make the necessary payments) before setting up his own taxi business and acquiring a Ford cars sub-agency and naming it Whitehouse Motors. When the second World War broke out, the motor business folded, but by then King had diversified into more general engineering work and so prospered from defence contracts and making parts for aircraft. He benefited hugely from War Ministry contracts and was able to use rare American machine tools that he acquired under the Lend Lease programme.
After the war King moved to Canada for a time, before returning to England and building a factory on wasteland in Ferrybridge, Yorkshire to establish Ferrybridge Industries. After renaming it the Pollard Ball and Roller Bearing Company and producing millions of ball bearings per year, it grew to become a major operation spanning several continents (the third-largest ball-bearing business in the UK). After being forced to merge the business with another manufacturer, Ransome & Marles, as part of a government reorganisation of the ball bearing business, King sold it for £10m in 1968, netting some £3m personally.