Robert Catesby Taliaferro (1907–1989) was an American mathematician, philosopher, and translator of ancient Greek and Latin works into English. An Episcopalian from an old Virginia family, he taught in the mathematics department of the University of Notre Dame. He translated Ptolemy'sAlmagest, a 2nd-century book on astronomy, the 13 books of Euclid's Elements, Apollonius' works on conic sections, and some works of Plato, and St. Augustine. He contributed a celebrated foreword to the Bollingen Series 1944 reprint of the Thomas Taylor translation of Plato's Timaeus and Critias. He also wrote a book titled The concept of matter in Descartes and Leibniz and one titled Number systems, introduction to Euclid book V, and to the theory of limits.