Herbert William Mullin (April 18, 1947 – August 18, 2022) was an American serial killer who killed 13 people in California in the early 1970s. He confessed to the killings, which he claimed prevented earthquakes. In 1973, after a trial to determine whether he was legally insane or culpable, he was convicted of two murders in the first-degree and nine in the second-degree and sentenced to life imprisonment. During his imprisonment, he was denied parole eight times.

Mullin and Edmund Kemper overlapped in their 1972 to 1973 murder sprees, adding confusion to the police investigations and ending with both being arrested within a few weeks of each other after the deaths of 21 people.