Arthur Donald Walsh FRS (8 August 1916 – 23 April 1977) was a British chemist, professor of chemistry at the University of Dundee. Walsh was educated at Loughborough Grammar School.
Walsh, usually known as Donald Walsh, was born in 1916 in Loughborough, Leicestershire. An alumnus of the University of Cambridge, he was awarded a Ph.D. in 1941 and thereafter became an ICI fellow. He was subsequently employed as a lecturer and reader at the University of Leeds for six years. In 1955 he left Leeds to assume the Baxter Chair of chemistry at Queen's College, Dundee, then a part of the University of St Andrews where he would spend the rest of his career. During his tenure he expanded the number of staff in his department, and attracted several research chemists via industrial research grants. When Queen’s College gained independence as the University of Dundee in 1967, he was appointed Dean of the Faculty of Science. As Dean of Science, he played a key role in creating a biochemistry department at the University. As convenor of the University of Dundee’s gardens sub-committee he was a prime mover in developing open spaces on the institutions main campus, notably Frankland Court, the establishment of which particularly pleased him.
In 1953 Walsh published a series of papers which introduced the Walsh diagrams, using molecular orbital energies as a function of bond angles to predict molecular geometry in both ground and excited states. His work on molecular spectroscopy and combustion was well respected and he was elected a Fellow of the Royal Society (FRS) in 1964. He was forced to retire from Dundee in 1976 due to failing health, and died the following year.
His extensive papers are held by Archive Services, University of Dundee.