The son of a publisher, Waugh was educated at Lancing College and then at Hertford College, Oxford, and briefly worked as a schoolmaster before he became a full-time writer. As a young man, he acquired many fashionable and aristocratic friends, and developed a taste for country house society. In the 1930s, he travelled extensively, often as a special newspaper correspondent; thus was he reporting from Abyssinia at the time of the 1935 Italian invasion. He served in the British armed forces throughout the Second World War (1939–1945), first in the Royal Marines and then in the Royal Horse Guards. He was a perceptive writer who used the experiences and the wide range of people he encountered in his works of fiction, generally to humorous effect. Waugh's detachment was such that he fictionalised his own mental breakdown, which occurred in the early 1950s.
After the failure of his first marriage, Waugh converted to Catholicism in 1930. His traditionalist stance led him to strongly oppose all attempts to reform the Church, and the changes by the Second Vatican Council (1962–65) greatly disturbed his sensibilities, especially the introduction of the vernacular Mass. That blow to his religious traditionalism, his dislike for the welfare state culture of the postwar world and the decline of his health, darkened his final years, but he continued to write. To the public, Waugh displayed a mask of indifference, but he was capable of great kindness to those whom he considered to be his friends.
After his death in 1966, he acquired a following of new readers, because of their exposure to the film and television versions of his works, such as the television serial ''Brideshead Revisited'' (1981).