Patrick Mackay (born September 25, 1952) is a serial killer who confessed to murdering eleven people in England in the early 1970s.

As a child, Mackay suffered a great deal at the hands of his violent, alcoholic father. In his youth, he indulged in animal cruelty and arson, bullied younger children and even attempted to kill his mother and aunt. He spent his teenaged years in and out of mental homes and institutions, and at fifteen, he was diagnosed as a psychopath by a psychiatrist. As he entered adulthood, Mackay developed a fascination with Nazism, calling himself "Franklin Bollvolt The First" and filling his flat with Nazi memorabilia.

On March 21, 1975, then aged twenty-two, Mackay used an axe to brutally kill a priest who had befriended him, hacking through the victim's skull and watching him slowly bleed to death. He was swiftly arrested and was soon considered by police to be a suspect in at least a dozen other killings over the past two-years, most victims being elderly women who had been stabbed or strangled to death during robberies. Mackay himself bragged that he had murdered eleven people.

Patrick Mackay was charged with five murders, but two charges were eventually dropped due to lack of evidence. In November 1975 he was convicted and sentenced to life imprisonment.