Sir David Gwynne Evans (6 September 1909 - 13 June 1984) was a British microbiologist. He studied at Manchester University from 1930 to 1933, when he graduated with a degree in physics and chemistry, and he gained his MSc in 1934. He finished his PhD in 1938 and began working at the National Institute for Medical Research two years later.[1] He left in 1947 to become areader in the bacteriology department at Manchester University, but returned to the NIMR in 1955 as director of the biological standards department. In 1961 he became professor of bacteriology and immunology at London School of Hygiene & Tropical Medicine, a position he left in 1971 to become director of the National Institute for Biological Standards and Control. He was awarded the Buchanan Medal of the Royal Society in 1977 for his work, and retired in 1979.[1]