Robert Davis Richtmyer (October 10, 1910 – September 24, 2003) was an American physicist, mathematician, educator, author, and musician.

[4] A letter sent March 11, 1947, from John von Neumann to Richtmyer outlined a technique for approximating complex problems being studied at Los Alamos by Stanislaw Ulam.

Richtmyer used the massive IBM SSEC calculator for some of the first large-scale uses of what would be called the Monte Carlo method.

[7][better source needed] Starting in 1964, he taught mathematics and physics at the University of Colorado at Boulder until his retirement in the early 1980s.

In 1990 he was awarded the Leroy P. Steele Prize from the American Mathematical Society for his book Difference Methods for Initial-Value Problems.