John Leonard King, Baron King of Wartnaby (29 August 1917 – 12 July 2005) was the businessman who made his name as head of British Airways in the 1980s, turning it from a loss-maker into a celebrated success.

John was raised in Surrey, leaving school aged 12 with no qualifications to his name, and starting work at a local vacuum cleaner factory. He later became a car salesman, then set up his own taxi business before acquiring a Ford cars sub-agent which he named Whitehouse Motors. At the outbreak of the Second World War, the motor business folded, but by then John had already diversified and was taking on defence contracts for the manufacture of aircraft parts. Under the Lend Lease programme, he was able to acquire and put to use American machine tools that were otherwise in short supply. After the war, he set up a company that became Britain’s third largest manufacturer of ball bearings, and sold it in 1968 for £10m.

In the 1970s, John became Chairman of Dennis Specialist Vehicles, and later of Babcock International, where he remained as chair after its acquisition-merger with FKI Electricals into FKI Babcock. He was appointed to the National Enterprise Board before becoming Chairman of the then much-criticised British Airways in 1981. The nationalised airline was losing more than £140m a year at this time, and John was tasked with preparing it for privatisation. With a focus on improved customer service, branding and advertising, and a tough but purpose-driven management style, he vastly improved public perception of the airline which, in 1989, was able to declare a pre-tax profit of £268m.

John Leonard King received a knighthood in 1979 and was made a life peer in 1983 as Baron King of Wartnaby in the County of Leicestershire.