Robert Peter Fleming, OBE (31 May 1907 – 18 August 1971) was a British adventurer and travel writer. He was the elder brother of Ian Fleming, creator of James Bond.
Peter Fleming was one of four sons of the barrister and MP Valentine Fleming, who was killed in action in 1917, having served as MP for Henley from 1910. Peter's younger brother Ian was the author of the James Bond books. Fleming was educated at Eton, where he edited the Eton College Chronicle. The Peter Fleming Owl (the English meaning of "Strix", the name under which he later wrote for The Spectator) is still awarded every year to the best contributor to the Chronicle. He went on from Eton to Christ Church, Oxford, and graduated with a first-class degree in English. He was a member of the Bullingdon Club during his time there. In 1935 he married the actress Celia Johnson (1908–1982), best known for her roles in the films Brief Encounter and The Prime of Miss Jean Brodie.
In April 1932 Fleming replied to an advertisement in the personal columns of The Times: "Exploring and sporting expedition, under experienced guidance, leaving England June to explore rivers central Brazil, if possible ascertain fate Colonel Percy Fawcett; abundant game, big and small; exceptional fishing; room two more guns; highest references expected and given." He then joined the expedition, organised by Robert Churchward, to São Paulo, then overland to the rivers Araguaia and Tapirapé, heading towards the last-known position of the Fawcett expedition. During the inward journey the expedition was riven by increasing disagreements as to its objectives and plans, centred particularly on its local leader, whom Fleming disguised as "Major Pingle" when he wrote about the expedition. Fleming and Roger Pettiward (a school and university friend recruited onto the expedition as a result of a chance encounter with Fleming) led a breakaway group.