Aleksandr Aleksandrovich Stackelberg (sometimes Shtakel'berg; Russian: Александр Александрович Штакельберг; 1897–1975) was a Russian entomologist. Stackelberg was born in St. Petersburg and specialised on Diptera, notably Syrphidae. He joined the staff of the Zoological Museum of the Academy of Sciences in 1920, and in 1929 he was made the Director of the Diptera Division. From 1942 he was the Head of the Department of Entomology. He taught entomology to I. A. Rubtsov, B. B. Rohdendorf, Ye. N. Savchenko, and N. A. Violovitch. He wrote over 160 scientific papers.