Born of 23rd of September 1917, in Tulancingo, Hidalgo, Rodolfo Guzmán Huerta was the fifth of seven children. He settled in Mexico City, where he practised baseball and American football, before becoming interested in wrestling. Trained by his older brother, Black Guzmán. Why stories differ, he began wrestling in the early 30s and was an established act by the late 30s. He turned to the name of el Santo because his first choices either didn't stick or, in the case of the Bat II, was already taken by more established wrestlers.
Through the 40s and 50s, el Santo would find fame and popularity through Mexico wrestling alongside the likes of the Blue Demon, Mil Máscaras, Black Shadow and los Guerreros (the family of Eddie Guerrero). He even defeated and unmasked Black Shadow, leading to a famous rivalry with the Blue Demon.