David Thoday FRS (5 May 1883 – 30 March 1964) was a botanist.
Thoday was Harry Bolus professor of botany, University of Cape Town and later professor at the University College of North Wales 1923âÂÂ1949. As a botanist, his work is denoted by the author abbreviation <span class="vcard"><span class="fn n"><span class="nickname">Thoday</span></span></span> when citing a botanical name.
He was elected a Fellow of the Royal Society in 1942. His nomination reads
He married fellow botanist and activist Mary Gladys Sykes in 1910. Their son was the geneticist John Thoday.