Georgy Pfeiffer also Yurii or Yury Pfeiffer (Russian: Гео́ргий Васи́льевич Пфе́йффер, German: Georg Ferdinand Pfeiffer, 23 December 1872 – 10 October 1946) was a Russian Empire and Soviet mathematician of German descent.

He was an Invited Speaker of the International Congress of Mathematicians (ICM) in 1908 at Rome,[2] in 1928 at Bologna,[3][4][5] and in 1932 at Zurich.

He was a chairman of the Academic Council of the Faculty of Physics and Mathematics at the University of Kiev, Russian Empire.

Pfeiffer was also attached to the Institute of Mathematics of the Academy of Sciences of the Ukrainian SSR in Kiev and served as Director during two periods, namely 1934 to 1941 and again from 1944 until his death in 1946.

In Ufa, Pfeiffer was Director of the Institute of Mathematics and Physics.