Barnaby Lenon was educated at a Direct Grant school and Oxford University, taught at Eton, Sherborne School, Holland Park comprehensive and Highgate School, and was head of Trinity School Croydon and Harrow School. He has been a governor of many schools, state and independent, and is chairman of governors of a free school, the London Academy of Excellence. He is on the boards of Ofqual, the New Schools Network, the Yellow Submarine charity for young people with learning disabilities, and chairs the Independent Schools Council.
In 2017 Barnaby Lenon, previously the head master of Harrow School, wrote a best-selling book about high-achieving state schools in England (Much Promise). Later that year he went on a tour of Further Education colleges and started to research the fortunes of those who do less well at school. In Other People's Children he writes about the state of vocational education in England and the implications of his findings for a post-Brexit economy.