Sir Edwin John Butler FRS (13 August 1874 – 4 April 1943) was an Irish mycologist and plant pathologist.
He became the Imperial Mycologist in India and later the first director of the Imperial Bureau of Mycology in England.
He was knighted in 1939..
During his twenty years in India, he began large scale surveys on fungi and plant pathology and published the landmark book Fungi and Disease in Plants: An Introduction to the Diseases of Field and Plantation Crops, especially those of India and the East (1918) and has been called the Father of Mycology and Plant Pathology in India.