Sir Herbert Stanley Marchant KCMG OBE (18 May 1906 – 8 August 1990) was a schoolmaster, at Bletchley Park the codebreaking centre in World War II, and then a diplomat. He was ambassador to Cuba (1960–63) and Tunisia (1963–66); remembered for replying to British newspapers during the Cuban Missile Crisis that “Everything is perfectly quiet here” (in Cuba). Marchant was born in Cambridge and attended Perse School, before studying modern languages at St John’s College, Cambridge. He was an assistant master at Harrow School 1928–39, teaching French and German, and later Russian.