Brian Simon (26 March 1915 – 17 January 2002) was an English educationist and historian.
The younger son of Ernest Darwin Simon, 1st Baron Simon of Wythenshawe and Shena, Lady Simon, he was the brother of the second Baron Simon of Wythenshawe, Roger Simon, the solicitor and writer on Gramsci.
After Gresham's School, Holt, Norfolk, where he was a contemporary of Benjamin Britten and Donald Maclean, and two terms at Schule Schloss Salem, under the headship of Kurt Hahn, Simon went up to Trinity College, Cambridge in 1934, becoming a leader of the University Education Society. In 1935 he joined the Communist Party of Great Britain (as his brother Roger would do a year later) and the student Marxist Study Group.
After Cambridge he went to the University of London's Institute of Education to train as a teacher.
In 1938, he was appointed to the newly formed Labour Party education advisory committee and was elected secretary of the National Union of Students branch at the Institute of Education, becoming president in 1939. He travelled to international student conferences, one such being with Guy Burgess in Moscow in the summer of 1939.
During the Second World War, Simon served in the Dorsetshire Regiment and the Royal Corps of Signals and was attached to the Phantom regiment (General Headquarters Liaison) which took him to many places and led to a lifelong friendship with the actor David Niven.