Ralph Martin Kaufmann (born August 4, 1969) is a German mathematician working in the United States.

His doctoral studies were carried out at the Max Planck Institute for Mathematics under the supervision of Yuri Manin, and he graduated summa cum laude from University of Bonn in 1997 with a thesis entitled "The geometry of the moduli space of pointed curves, the tensor product in the theory of Frobenius manifolds and the explicit Künneth formula in quantum cohomology".

[7] In collaboration with Yuri Manin and Don Zagier he started the study of higher Weil–Peterson volumes,[8] later continued by Losef–Manin and Maryam Mirzakhani.

[11][12] Kaufmann has also worked on string topology, invented by Moira Chas and Dennis Sullivan, and operad theory.

[13][14][15][16][17] Here he first proved a cyclic version of Pierre Deligne's conjecture in deformation theory[18] and provided an extension of string topology to moduli spaces.