Sir Robert Birley KCMG (14 July 1903 – 22 July 1982) was an English educationalist who was head master of Charterhouse School, then Eton College, and an anti-apartheid campaigner. He acquired the nickname "Red Robert", as even his moderate liberal politics caused concern for the conservative members of the Eton school of governors. His predecessor, Claude Aurelius Elliott was appointed provost and in his capacity as chair of the board of governors, living next door to Birley, he was able to keep an eye on Robert.
Birley was educated at Rugby and Balliol. He began his career as a history master at Eton in 1926 and in 1935 was appointed as headmaster of Charterhouse. During this time, he was the principal author of the Fleming Report of 1944 on the relationship between the public schools and mainstream education.
In 1947, after the Second World War, he became Educational Advisor to the Control Commission in the British Zone in Germany, responsible for educational reconstruction, and played an important role in the rewriting of Nazi history textbooks, removing their racist bent. From 1947 to 1949 he gave important support to Lilo Milchsack who formed the Anglo-German Association to improve post-war relations. Birley returned to support these efforts after he left Germany in 1949.
In 1949 he was appointed Head Master of Eton, where he remained until 1963. Also in 1949, he was invited by the BBC to deliver the annual Reith Lectures. The radio broadcasts were titled Britain in Europe: Reflections on the Development of a European Society.