Joan Olivia Wyndham (11 October 1921, East Knoyle, Wiltshire – 8 April 2007, London) was a British writer and memoirist who rose to literary prominence late in life through the diaries she had kept more than 40 years earlier, which were an account of her romantic adventures during the Second World War, when she was an attractive teenager who had strayed into London's Bohemian set. Her literary reputation rests on Love Lessons (1985) and Love Is Blue (1986), two selections from her diaries which led one critic to call her "a latterday Pepys in camiknickers."
Wyndham's mother, Iris Bennett, was an ex-débutante and the illegitimate daughter of senior Army officer Sir John French; her father, Guy Richard Charles ("Dick") Wyndham (1896–1948), son of Guy Wyndham, was from the aristocratic Wyndham family of Petworth House, West Sussex. Her early years were spent in the Wiltshire countryside at the family residence, Clouds House. Her parents' marriage was failing by the time Joan was born, and they separated when she was four. After the divorce, mother and daughter went to live in west London, at 22 Evelyn Gardens, off Fulham Road, and sought solace in devout Roman Catholicism. Together, they attended Mass every day and confession once a week. Joan was sent to a Catholic boarding school, and developed a passion for the theatre and later art.
After her father, Dick Wyndham, was caught In flagrante delicto with the Marchioness of Queensbury, he followed the custom of the period by registering at a hotel in Brighton where he arranged for a private detective to photograph him in bed with a prostitute, rather than embarrass his lover. He later worked as a correspondent for The Sunday Times and was sent to the Middle East. In May 1948, while covering the 1948 Arab-Israeli War, he was killed by Israeli machine-gun fire in Jerusalem while photographing an Arab advance from a forward Arab Legion post.