Professor David Gawen Champernowne FBA (9 July 1912 – 19 August 2000) was an English economist and mathematician.
Champernowne was educated at Winchester and King's College, Cambridge, where he was a contemporary and friend of Alan Turing. After academic work there and at the London School of Economics, he was drafted in to the statistical section of the prime minister's office at the beginning of the Second World War to supply quantitative information to help Winston Churchill make decisions; then, in 1941, he moved on to become a programme director in the Ministry of Aircraft Production.
He was Professor of Statistical Economics at the University of Oxford (1948–1959), and Professor of Economics and Statistics at the University of Cambridge (1970–2000).
He published work on Champernowne constant in 1933, whilst still an undergraduate at Cambridge. In 1948, working with his old college friend Alan Turing, he helped develop one of the first chess-playing computer programs. The book for which he is most renowned, synthesising a life's work, Economic Inequality and Income Distribution (Cambridge University Press), was published in 1998.
His co-editors at the Economic Journal found him to be "modest, quirky and humorous".
His grave is at the new church at Dartington in Devon, built by his family in the 1870s to replace the ancient church at Dartington Hall, the family seat.