Testament is an American thrash metal band from Berkeley, California. Formed in 1983 under the name Legacy, the band's current lineup comprises guitarists Eric Peterson and Alex Skolnick, lead vocalist Chuck Billy, drummer Gene Hoglan, and bassist Steve Di Giorgio. In the 35 years since its inception, Testament has had numerous lineup changes, and Peterson has been the only constant member. Billy replaced original singer Steve "Zetro" Souza (who left the band to join Exodus as the replacement of Paul Baloff) in 1986, prior to the recording of their first studio album, The Legacy, and has been a member of the band since. Peterson and Billy are the only band members to appear on every album.

Testament is often credited as one of the most popular and influential bands of the thrash metal scene, having sold over 1.4 million albums in the United States since the beginning of the SoundScan era and over 4 million copies worldwide. They are also often credited as one of the leaders of the second wave of thrash metal in the late 1980s, along with bands such as Sacred Reich, Death Angel, Destruction and Dark Angel. To date, the band has released eleven studio albums, four live albums, six compilation albums, twelve singles and three DVDs.