David A. Turner (born 26 January 1946) is a British computer scientist. He is best known for designing and implementing three programming languages, including the first for functional programming based on lazy evaluation, combinator graph reduction, and polymorphic types: SASL (1972), Kent Recursive Calculator (KRC) (1981), and the commercially supported Miranda (1985). Miranda had a strong influence on the later Haskell. He is also an Emeritus Professor at Middlesex University, England.