Brian Butterworth FBA (born 3 January 1944) is emeritus professor of cognitive neuropsychology in the Institute of Cognitive Neuroscience at University College London.
His research has ranged from speech errors and pauses, short-term memory deficits, dyslexia, reading both in alphabetic scripts and Chinese, and mathematics and dyscalculia.
His book The Mathematical Brain has been translated into four languages.
He was Editor-in-Chief of Linguistics (1978–1983) and a founding editor of the journals Language and Cognitive Processes and Mathematical Cognition.
He is a Fellow of the British Academy.
In 1984 he diagnosed President Ronald Reagan on the basis of speech errors in his presidential re-election speeches in an article in the Sunday Times as having Alzheimer's disease ten years before this was formally identified.
He was a coauthor in 1971 of a pamphlet, Marked for life, critical of university examinations.He designed the world's largest mathematical experiment involving over 18,000 people at Explore-At-Bristol.
In the serious game for elementary school children with dyscalculia, Meister Cody, he lends his voice to Quoun, the Guardian of the Trees.