AC/DC are an Australian hard rock band formed in Sydney in 1973 by brothers Malcolm and Angus Young. Although the band members are considered pioneers of heavy metal, they have always classified their music as "Rock n' roll".

AC/DC underwent several line-up changes before releasing their first album, High Voltage, in 1975. Membership remained stable until bassist Mark Evans was replaced by Cliff Williams in 1977. In 1979, the band recorded their highly successful album Highway to Hell. Lead singer and co-songwriter Bon Scott died on 19 February 1980, after a night of heavy alcohol consumption. The group briefly considered disbanding, but soon ex-Geordie singer Brian Johnson was selected as Scott's replacement. Later that year, the band released their best-selling album, Back in Black.

The band's next album, For Those About to Rock We Salute You, was also highly successful and was their first album to reach number one in the United States. AC/DC declined in popularity soon after drummer Phil Rudd was fired in 1983 and replaced by future Dio drummer Simon Wright. Poor record sales continued until the release of The Razors Edge in 1990, the only studio album to feature Wright's replacement Chris Slade. Phil Rudd returned in 1994 (after Slade was asked to leave in favor of him) and contributed to the band's 1995 album Ballbreaker. Stiff Upper Lip was released in 2000 and was well-received by critics. The band's new album Black Ice was announced in June 2008 and was released on 20 October 2008.

AC/DC have sold more than 200 million albums worldwide, including 69 million albums in the United States. Back in Black has sold an estimated 42 million units worldwide and 22 million in the United States alone, where it is the fifth highest-selling album. AC/DC ranked fourth on VH1's list of the "100 Greatest Artists of Hard Rock" and the seventh "Greatest Heavy Metal Band Of All Time" by MTV. In 2004, the band was ranked number 72 in the Rolling Stone list of the 100 Greatest Artists of All Time.

AC/DC were inducted into the Rock and Roll Hall of Fame on March 10, 2003. During the ceremony the band performed "Highway to Hell" and "You Shook Me All Night Long", with guest vocals provided by host Steven Tyler of Aerosmith. He described the band's power chords as "the thunder from down under that gives you the second-most-powerful surge that can flow through your body." During the acceptance speech, Brian Johnson quoted their 1977 song "Let There Be Rock".

In May 2003, Malcolm Young accepted a Ted Albert Award for Outstanding Service to Australian Music at the 2003 Music Winners Awards, during which he paid special tribute to Bon Scott.

On 1 October 2004, a central Melbourne thoroughfare, Corporation Lane, was renamed ACDC Lane in honour of the band. However, the City of Melbourne forbade the use of the slash character in street names, so the four letters were combined. The lane is near Swanston Street where, on the back of a truck, the band recorded their video for the 1975 hit "It's a Long Way to the Top (If You Wanna Rock 'n' Roll)". Additionally, a street in Leganés (Comunidad de Madrid – Spain), was named "Calle de AC/DC" on 2 March 2000.

Since Nielsen SoundScan began to track music sales in 1991, AC/DC have sold over $26.4? million worth of albums, making their sales figures second only to The Beatles, outselling both The Rolling Stones and The Who. Over the last five years, as CD sales have declined in general, AC/DC albums have sold just as well or better. They sold over 1.3 million CDs in the US during 2007 despite not having released a new album since 2001 at that point.

In 2009 the Recording Industry Association of America upgraded the group's US sales figures from 69 million to 71 million, making AC/DC the fifth-best-selling band in US history and the ninth-best-selling artist, selling more albums than Madonna, Mariah Carey and Michael Jackson. The RIAA also certified Back in Black as double Diamond (20 million) in US sales, and by 2007 the album had sold 22 million copies, which moved it into fifth place.

In 2010, AC/DC won a Grammy Award for Best Hard Rock Performance with 'War Machine' off their fifteenth studio album, 'Black Ice.'