Hanneman was born January 31, 1964, in Oakland, California, and grew up in Long Beach in a family containing several war veterans: his father fought in Normandy during World War II and his brothers in Vietnam, making warfare a common conversation topic at the dinner table. War films were popular on TV at the time, and Hanneman often joined his brothers in constructing and coloring tank and plane models. His interest in warfare and military history has been attributed to his upbringing.

In a 2009 interview with Decibel magazine, he stated his father is German, but fought for the Allied side in World War II. In the same interview, he also goes into detail of what district of Germany his father and grandparents hail from. His grandfather was fluent in German.  Hanneman was introduced to heavy metal music as a child through his older sister Mary, when she was listening to Black Sabbath at her house. Once he reached high school, he discovered hardcore punk, which had a significant influence on his style and attitude.

In 1981 Hanneman, who was working as a telemarketer at the time, met Kerry King, when King was auditioning for a southern rock band called “Ledger”. King remembered: “As I was leaving, I saw Jeff just kinda standing around playing guitar, and he was playing stuff that I was into, like Def Leppard’s ‘Wasted’ and AC/DC and Priest”. After the try-out session, the two guitarists started talking and playing Iron Maiden and Judas Priest songs. Slayer was born when King asked “Why don’t we start our own band?”, to which Hanneman replied “…Fuck yeah!”.

Hanneman stated that he was playing guitar “for like a month” by the time he met King and put an effort into improving his skills after watching him play. Hanneman, who was heavily influenced by hardcore punk music, got the other members into the genre, leading Slayer into a faster and more aggressive approach. The band’s drummer Dave Lombardo asserted that his hardcore influences pushed him to play faster, contributing to shape his drumming style.

In 1984, Hanneman, Lombardo and Suicidal Tendencies guitarist Rocky George had a brief hardcore punk side project called “Pap Smear” – the band had many tracks and was due to start recording when Hanneman was advised to avoid the side project by Slayer’s producer, Rick Rubin, who is quoted as saying “Ahhhh, don’t do it, man — this is the kind of thing that breaks bands up!” and Hanneman took Rubin’s advice. Only a demo was recorded, consisting of Hanneman on vocals and bass, Lombardo on drums and George on guitar. Later two of the songs were re-recorded on Slayer’s 1996 album Undisputed Attitude.

In early 2011, Hanneman contracted necrotizing fasciitis. Reports linked this illness with a spider bite he claimed to have received while in a friend’s hot tub.  In light of his illness and Slayer’s upcoming participation in the Australian Soundwave Festival tour that was set to begin on February 26, 2011, the band made the decision to play the dates without Hanneman, and on February 16, 2011, brought on Gary Holt (guitarist of the band Exodus) to fill in for him. Pat O’Brien joined as Slayer’s temporary second guitarist when Holt left the tour to play with Exodus. In 2012, bandmate Tom Araya announced a recovery from the disease. However, later in February 2013, Kerry King revealed continuing health problems that kept Hanneman from working.  Hanneman died of liver failure on May 2, 2013, in a Southern California hospital near his home. On May 9, 2013, the official cause of death was announced as alcohol-related cirrhosis. Hanneman and his family had apparently been unaware of the extent of the condition until shortly before his death.