Avenged Sevenfold (abbreviated as A7X) is an American heavy metal band from Huntington Beach, California, formed in 1999. The band's current lineup consists of lead vocalist and pianist M. Shadows, rhythm guitarist and backing vocalist Zacky Vengeance, lead guitarist, pianist, and backing vocalist Synyster Gates, bassist and backing vocalist Johnny Christ, and drummer Brooks Wackerman.

Avenged Sevenfold are known for their diverse rock sound and dramatic imagery in album covers and merchandise. The band emerged with a metalcore sound on their debut album Sounding the Seventh Trumpet and continued this sound through their second album Waking the Fallen. However, the band's style had evolved by the group's third album and first major label release, City of Evil, into a heavy and progressive metal style. The band continued to explore new sounds with its self-titled release and enjoyed continued mainstream success before their drummer, James "The Rev" Sullivan, died in 2009. Despite his death, Avenged Sevenfold continued on with the help of drummer Mike Portnoy (ex-Dream Theater), and released and toured in support of their fifth album Nightmare in 2010, which debuted on atop the Billboard 200, their first number one debut.

In 2011 drummer Arin Ilejay joined the band on tours and recording. The band's sixth studio album Hail to the King, which was released in 2013, marked the only Avenged Sevenfold album featuring Ilejay. Hail to the King charted as number 1 on the Billboard 200, the UK Albums chart, as well as the Finnish, Brazilian, Canadian, and Irish charts. In late 2014, Ilejay left the band, and was replaced by former Bad Religion drummer Brooks Wackerman, but the lineup change was not announced to the public until 2015. The band then surprise-released their seventh studio album titled The Stage on October 28, 2016, which debuted as number 4 on the Billboard 200 chart in the US. The Stage is their first conceptual album and it marked another stylistic change for the band, moving again towards a progressive metal sound. The band are set to release their eighth studio album, Life Is but a Dream... on June 2nd, 2023.

To date, Avenged Sevenfold have released seven studio albums, one live album/DVD, two compilation albums and eighteen singles and have sold over 8 million albums worldwide, and their records have received numerous certification awards, including five platinum album awards from their home country's institution (RIAA). They have also created four original songs for the Call of Duty: Black Ops series, all of which were compiled together in the 2018 EP Black Reign. The band were ranked No. 47 on Loudwire's list of Top 50 Metal Bands of All Time.