Henry George "Harry" Thode CC MBE FRS FRSC (September 10, 1910 – March 22, 1997) was a Canadian geochemist, nuclear chemist, and academic administrator. He was president and vice-chancellor of McMaster University from 1961 to 1972. Thode built a cyclotron capable of making radioactive isotopes and along with Dr. C.H. Jaimet, investigated the use of radioactive iodine in the diagnosis and treatment of thyroid disease in humans, the first medical application of radioactive iodine in Canada.