Helmar Gunter Frank (19 February 1933, Waiblingen – 15 December 2013, Paderborn) was a German mathematician and pedagogist. He was among the first scientists to apply mathematical methods in teaching and psychology. He established a method to measure intelligence on an absolute and homogeneous scale rather than by comparison between individuals. In the late 1970s and early 1980s he was the initiator and scientific evaluator of an international teaching experiment on the propaedeutic value of Esperanto. Frank's wife, Věra Barandovská-Frank, is a well-known Czech Esperantist.