Alexander Mikhailovich Nikolsky (February 18, 1858 – December 8, 1942) was a Russian zoologist born in Astrakhan.
From 1877 to 1881 he studied at the University of St. Petersburg, earning his doctorate several years later in 1887. From 1881 to 1891 he took part in numerous expeditions to Siberia, the Caucasus, Persia, Japan, et al. In 1887 he became an associate professor in St. Petersburg, and in 1895 became director of the herpetology department at the Zoological Museum of the Academy of Sciences.
In 1903 he relocated as a professor to the Kharkiv University, and in 1919 was elected a member at the Academy of Sciences of the Ukraine. Among his written works were Herpetologia Caucasica (1913), and volumes on reptiles and amphibians which were part of the series "Fauna of Russia and Adjacent Countries".