George Johann Klein, OC MBE (August 15, 1904 – November 4, 1992) was a Canadian inventor who is often called the most productive inventor in Canada in the 20th century. Although he struggled as a high school student, he eventually graduated from the University of Toronto in Mechanical Engineering. His inventions include key contributions to the first electric wheelchairs for quadriplegics, the first microsurgical staple gun, the ZEEP nuclear reactor which was the precursor to the CANDU reactor, the international system for classifying ground-cover snow, aircraft skis, the Weasel all-terrain vehicle, the STEM antenna for the space program, and the Canadarm.

Klein worked for forty years as a mechanical engineer at the National Research Council of Canada laboratories in Ottawa (1929–1969).^[1]

In 1968, he was made an Officer of the Order of Canada. In 1995, he was inducted to the Canadian Science and Engineering Hall of Fame.^[2]