Aloysius Martin Thesz (April 24, 1916 – April 28, 2002), known by the ring name Lou Thesz, was an American professional wrestler and wrestling coach. Considered to be one of the last true shooters (legitimate wrestlers) in professional wrestling and described as the "quintessential athlete" and a "polished warrior who could break a man in two if pushed the wrong way", Thesz is widely regarded as one of the greatest wrestlers and wrestling world champions in history, and possibly the last globally accepted world champion.
Thesz won various version of the World Heavyweight Championship seven times, including three reigns as NWA World Heavyweight Champion, which he held for a combined total of ten years, three months and nine days (3,749 days) – longer than anyone else in history. In Japan, Thesz was known as the "God of Wrestling'" (like his Belgian counterpart, Karl Gotch) and was called "Tetsujin", which means "Ironman", in respect for his speed, conditioning and expertise in catch wrestling. Alongside Karl Gotch and Billy Robinson, Thesz later helped train young Japanese wrestlers and mixed martial artists in catch wrestling.