Grigorii Mikhailovich Fikhtengol'ts (Russian: Григо́рий Миха́йлович Фихтенго́льц, Ukrainian: Григорій Михайлович Фіхтенгольц, romanized: Hryhorii Mykhailovych Fikhtenholts; 8 June[1] 1888 – 26 June 1959) was a Soviet mathematician working on real analysis and functional analysis.

He authored a three-volume textbook titled "A Course of Differential and Integral Calculus".

Due to the depth and precision of the material's presentation, the book holds a classical position in the mathematical literature.

It has been translated into several languages, including German, Ukrainian, Polish, Chinese, Vietnamese, and Persian.

For unknown reasons, these books have not gained the same level of fame in universities in other parts of the world.