Ian Lancaster Fleming (28 May 1908 – 12 August 1964) was a British writer, best known for his postwar James Bond series of spy novels. Fleming came from a wealthy family connected to the merchant bank Robert Fleming & Co., and his father was the Member of Parliament (MP) for Henley from 1910 until his death on the Western Front in 1917. Educated at Eton, Sandhurst, and, briefly, the universities of Munich and Geneva, Fleming moved through several jobs before he started writing.

While working for Britain's Naval Intelligence Division during the Second World War, Fleming was involved in planning Operation Goldeneye and in the planning and oversight of two intelligence units: 30 Assault Unit and T-Force. He drew from his wartime service and his career as a journalist for much of the background, detail, and depth of his James Bond novels.

Fleming wrote his first Bond novel, Casino Royale, in 1952, at age 44. It was a success, and three print runs were commissioned to meet the demand. Eleven Bond novels and two collections of short stories followed between 1953 and 1966. The novels centre around James Bond, an officer in the Secret Intelligence Service, commonly known as MI6. Bond is also known by his code number, 007, and was a commander in the Royal Naval Volunteer Reserve. The Bond stories rank among the best-selling series of fictional books of all time, having sold over 100 million copies worldwide. Fleming also wrote the children's story Chitty-Chitty-Bang-Bang (1964) and two works of non-fiction. In 2008, The Times ranked Fleming 14th on its list of "The 50 greatest British writers since 1945".

Fleming was married to Anne Charteris. She had divorced her husband, the 2nd Viscount Rothermere, because of her affair with the author. Fleming and Charteris had a son, Caspar. A heavy smoker and drinker for most of his life, Fleming died from complications of heart disease in 1964, at the age of 56. Two of his James Bond books were published posthumously; other writers have since produced Bond novels. Fleming's creation has appeared in film twenty-seven times, portrayed by six actors in the official film series.

Ian Lancaster Fleming was born on 28 May 1908, at 27 Green Street in the wealthy London district of Mayfair. His mother was Evelyn "Eve" Fleming, née Rose, and his father was Valentine Fleming, the Member of Parliament for Henley from 1910 to 1917. As an infant he briefly lived with his family at Braziers Park in Oxfordshire. Fleming was a grandson of the Scottish financier Robert Fleming, who co-founded the Scottish American Investment Company and the merchant bank Robert Fleming & Co.

In 1914, with the start of the First World War, Valentine Fleming joined "C" Squadron of Queen's Own Oxfordshire Hussars, and rose to the rank of major. He was killed by German shelling on the Western Front on 20 May 1917. Winston Churchill wrote an obituary for him that appeared in The Times. Because Valentine had owned an estate at Arnisdale, his death was commemorated on the Glenelg War Memorial.

Fleming's elder brother Peter became a travel writer and married actress Celia Johnson. Peter served with the Grenadier Guards during the Second World War, was later commissioned under Colin Gubbins to help establish the Auxiliary Units, and became involved in behind-the-lines operations in Norway and Greece during the war.

Fleming had two younger brothers, Richard and Michael, who also served in the Second World War. Richard served with Scottish regiments (Lovat Scouts and Seaforth Highlanders) and was the father of author, James Fleming. Michael died of wounds in October 1940 after being captured at Normandy while serving with the Oxfordshire and Buckinghamshire Light Infantry. Fleming also had a younger maternal half-sister born out of wedlock, the cellist Amaryllis Fleming (1925–1999), whose father was the artist Augustus John. Amaryllis was conceived during a long-term affair between John and Evelyn which had started in 1923, six years after the death of Valentine.