Vladimir Aleksandrovich Wagner (or Vagner: Russian: Владимир Александрович Вагнер; March 29, 1849 – March 8, 1934) was a Russian psychologist and naturalist known for his studies of comparative and evolutionary psychology. He also studied spiders, and in 1882 proposed the first classification of spider families based on copulatory organs. He studied law at Moscow University and from 1882, the natural sciences. After earning a doctorate in zoology, he began teaching 1895 at the Institute of Psycho-Neurology St. Petersburg.