Spahn grew up in the greater Philadelphia area. His father died in a work accident, when he was just two years old. Spahn had at times a tense relationship with his stepfather, who often exposed vicious and violent behaviour when he was drunk. Spahn left school already after the third grade and started to work as milkman. When he was 16 Spahn started an apprenticeship with a carpenter, however he didn't stay in this profession and eventually returned to the milk delivery business. He set up a business in Willow Grove owning five carriages and seven horses. He also employed his stepfather at this point. Before he was 30 Spahn acquired a farm of 86 acres in Lansdale, where he kept 36 cows and some horses. He married the widow Martha Virginia Greenholtz, who he originally had hired as a housekeeper for his farm. The couple had ten children together and a daughter from Greenholtz first marriage. In the early 1930s during the great depression Spahn's milk business was facing difficulties and he felt somewhat disenchanted with his life in general. This led him to start over in California. He sold his farm and moved his family and favorite horses to Los Angeles. There he gave up on the milk business and turned to raising horses and offering horse riding. In the late 1940 he separated from his wife and in 1953 he bought the movie ranch now carrying his name.
Spahn continued to raise horses and to offer horse riding trips. He also extended the already existing western film sets of the ranch and rented them out to film and TV productions. However due to declining demand for Western productions his business went bankrupt in 1966. After Spahn continued to live on the ranch with most of its buildings, in particular the film sets, being in disrepair. Spahn is chiefly remembered for his association with the MansonFamily, due to his tolerance of the Manson group's residence on his property. At the ranch, Spahn housed Charles Manson and his followers from 1968 on. The 1969 murders of actress Sharon Tate and six others by Manson's devotees were allegedly hatched at the Spahn Ranch. Manson persuaded Spahn to permit "the Family" to live at his ranch. Manson ordered the women in the group to clean and cook for the nearly blind 80-year-old. The women also acted as seeing eye guides for Spahn. Spahn nicknamed all the Manson girls, including Squeaky, Sadie Mae, and Ouisch. According to Manson Family member Paul Watkins, Mansonite Lynette "Squeaky" Fromme got her nickname because of the sound she made when Spahn ran his hand up her thigh. Family member Charles Watson has written that his own nickname, "Tex", was given to him by Spahn, who recognized his Texas accent. Spahn lived five years after the murders. For the first year he still stayed on the ranch with some of the women of the Manson family until it was destroyed in a large wildfire in September 1970. He was eventually admitted to the Sherwood Convalescent Hospital in Van Nuys, where he died on September 22, 1974, at the age of 85. He was buried in Eternal Valley Memorial Park in nearby Newhall. In September 1970, the Spahn Ranch, along with much of Chatsworth, burned down in a major brushfire.
Spahn himself can be seen as an old man in the 1973 documentary Manson. In the 1976 TV movieHelter Skelter based on the prosecutor Vincent Bugliosi's book of the same name Spahn is portrayed by Ray Middleton. In Quentin Tarantino's 2019 film Once Upon a Time in Hollywood, Spahn was portrayed by Bruce Dern. Burt Reynolds was initially cast as Spahn, but died in September 2018, a couple of weeks before shooting was slated to begin. In the 2018 film Charlie Says, Spahn is portrayed by John Gowans.
