Sir Thomas Percy Nunn (1870 – 1944) was a British educationalist, original member of the British Psychological Society and the First Chairman of the Education Section. He began his career as a secondary school teacher in 1891, and during the next ten years developed methods of teaching which revolutionised the teaching of mathematics in the UK. In 1903 he joined the staff of the London Day Training college, progressing from part-time lecturer to eventually become Professor of Education at the University of London, and in 1922 was appointed Principal. He published a number of books of fundamental importance on a variety of educational subjects. His approach was that of a realist philosopher whose main con- cern was to reconcile psychological with scientific judgments, examining as carefully as possible the data of experience in order to find the princi- ples which held the data together.

T. Percy Nunn was president of the Aristotelian Society from 1923-1924.