Arthur Louis Arthurovič de Jaczewski also as Artur Arturovich Yachevsky (Russian: Арту́р Арту́рович Яче́вский; 3 November 1863[1] – 12 February 1932) was a Russian biologist who was involved in studies on plant pathogenic fungi (particularly rusts and mildews) and was involved in the application of phytopathology to agronomy. The genera Jaczewskia and Jaczewskiella are named after him. His son Petr Arturovich Jaczewski (1908-1942) was also a mycologist.