Guns N' Roses is an American hard rock band formed in Los Angeles, California, in 1985, as the result of a merger between local bands Hollywood Rose and L.A. Guns. When they signed to Geffen Records in 1986, the band's "classic lineup" consisted of vocalist Axl Rose, lead guitarist Slash, rhythm guitarist Izzy Stradlin, bassist Duff McKagan, and drummer Steven Adler. The current lineup consists of Rose, Slash, McKagan, guitarist Richard Fortus, drummer Frank Ferrer and keyboardists Dizzy Reed and Melissa Reese.

Guns N' Roses heavily toured the West Coast club circuit during their early years before embarking on the Appetite for Destruction Tour. Their debut album Appetite for Destruction (1987) failed to gain traction, debuting at number 182 on the Billboard 200, until a year after its release when a grassroots campaign for the "Welcome to the Jungle" music video brought the band mainstream popularity. "Welcome to the Jungle" and "Paradise City" both became top 10 singles, with "Sweet Child o' Mine" becoming the band's only single to reach number one on the Billboard Hot 100. The album has sold approximately 30 million copies worldwide, including 18 million units in the United States, making it the country's best-selling debut album and eleventh-best-selling album. With their stylistic mix of punk rock, blues rock and heavy metal, the band helped move mainstream rock away from the glam metal era of the mid-late 1980s. In addition, they are credited with revitalizing power ballads in rock. Their next studio album, G N' R Lies (1988) combined an early EP, Live ?!*@ Like a Suicide (1986), with new acoustic songs and reached number two on the Billboard 200, sold ten million copies worldwide (including five million in the U.S.), and included the top 5 hit "Patience" and the controversial "One in a Million". Adler was fired due to his drug addiction in 1990 and was replaced by Matt Sorum.

Use Your Illusion I and Use Your Illusion II, recorded and released simultaneously in 1991, debuted at number two and number one on the Billboard 200 respectively and have sold a combined 35 million copies worldwide (including 14 million units in the U.S.). The Illusion albums included the lead single "You Could Be Mine", covers of "Live and Let Die" and "Knockin' on Heaven's Door", and a trilogy of ballads ("Don't Cry", "November Rain", and "Estranged"), which featured notably high-budget music videos. The records were supported by the Use Your Illusion Tour, a world tour that lasted from 1991 to 1993. Stradlin abruptly left the band near the beginning of the tour in 1991, replaced by Gilby Clarke. The punk covers album "The Spaghetti Incident?" (1993) was the last studio album to feature Stradlin and Sorum, the only to feature Clarke, and the last for Slash and McKagan before their initial departure. While mostly well received, it was the band's worst-selling studio album to date and was not supported by a tour.

Work on a follow-up album stalled due to creative differences and personal conflicts between Rose and other members; Slash and McKagan left the band while Clarke and Sorum were fired. In 1998 Rose, Reed, guitarists Paul Tobias and Robin Finck, bassist Tommy Stinson, drummer Josh Freese and multi-instrumentalist Chris Pitman started writing and recording new songs. Guitarists Buckethead, Bumblefoot and Fortus, and drummers Brain and Ferrer all contributed as the band's lineup changed. Their upcoming sixth studio album, Chinese Democracy (2008), was promoted with the expansive Chinese Democracy Tour (2001–2011). With Rose failing to deliver the album on schedule, Geffen released Greatest Hits (2004), which became the 8th longest-charting album in the history of the Billboard 200, reaching 631 weeks by July 2023. The long-awaited Chinese Democracy was released in November 2008, featuring the title track as the lead single. At an estimated $14 million in production costs, it is the most expensive rock album in history. It debuted at number three on the Billboard 200 with a generally positive critical reception. Slash and McKagan rejoined the band in 2016 for the quasi-reunion Not in This Lifetime... Tour, which became one of the highest-grossing concert tours of all time, grossing over $584 million by its conclusion in 2019.

In their early years, the band's hedonism and rebelliousness drew comparisons to the early Rolling Stones and earned them the nickname "the most dangerous band in the world". Significant controversy followed the band due to late show starts and riots (notably the 1991 Riverport riot), lyrics perceived as problematic, Rose's outspoken persona, several other members' drug and alcohol abuse issues, lawsuits, and public feuds with other artists. Several members of the band are considered among the best in their fields, with Rose considered one of the best vocalists, Slash as one of the best guitarists and McKagan as one of the best bassists by various publications. Guns N' Roses (Rose, Stradlin, McKagan, Slash, Adler, Sorum and Reed) were inducted into the Rock and Roll Hall of Fame in 2012. Guns N' Roses have sold more than 100 million records worldwide, including 45 million in the United States, making them one of the best-selling bands in history.