One of the Big 4 (the others are Sony BMG Music Entertainment, Universal Music Group and EMI Group) with 11.3% share of the global music market.

Its roots date back to 1963, when Warner Bros. Records acquired Frank Sinatra's Reprise Records label. In 1967, Warner/Reprise's parent corporation Warner-Seven Arts purchased Atlantic Records and its subsidiary labels. From 1967 to 1969, Atlantic/Atco operated under the umbrella of the parent corporation, but remained independent from Warner Brothers/Reprise.

In 1969, The Kinney Corporation purchased the Warner and Atlantic label companies. In mid 1970, Kinney acquired Elektra Records and formed Warner-Elektra-Atlantic (WEA). Though the three label groups competed against one another under the control of the parent corporation, WEA established a regional distribution system throughout the USA that enabled their labels to control a key sector of their business, circumvent the independents and compete head to head with other major labels of their day.

In 1972, Kinney changed the corporate name to Warner Communications. In 1987, the company merged with Time Inc. and the multi-media conglomerate Time Warner was formed. After a shortsighted merger with AOL in 2000, AOL-Time Warner was forced to spin off the label group in an attempt to reduce its debt. A deal to sell the labels to a group of investors led by Edgar Bronfman for $2.6 billion was reached in February 2004. Shortly after the acquisition, the corporation was renamed Warner Music Group.

Warner Music Group is comprised of 7 corporate divisions. WMG labels include Atlantic Records Group (Atlantic Records, Elektra Records, Bad Boy Records, Lava Records), Independent Label Group (including Asylum Records, Rhino Eentertainment, Rykodisc Records and subsidiary labels), Warner Bros. Records (including Maverick Records, Nonesuch Records, Reprise Records, Sire Records) and Warner Music International (including London Records).