This is a list of the world's best-selling albums of recorded music in physical mediums, such as vinyl, audio cassettes or compact discs. To appear on the list, the figure must have been published by a reliable source and the album must have sold at least 20 million copies and certified at least 10 million units (the equivalent of a diamond certification by the RIAA). This list can contain any types of album, including studio albums, extended plays, greatest hits, compilations, various artists, soundtracks and remixes. The figures given do not take into account the resale of used albums. Certified copies are sourced either from available online databases of local music industry associations or a country with an established certifying authority (see List of music recording certifications).
As a result of the methodology that the American and Canadian certification-awarding bodies (the RIAA and Music Canada respectively) use, each disc in a multi-disc set is counted as one unit toward certification, leading to many double albums on the list—such as Pink Floyd's The Wall and the Beatles' The Beatles (White Album) —being certified with a number double the number of copies sold there. Such albums have the certifications for the number of copies (not discs) shipped indicated. Conversely, the American certification level for double albums that fit onto one compact disc, such as the Saturday Night Fever soundtrack reflect the actual number of copies sold. In 2016, RIAA included streaming in addition to track sales and album sales based on the concept of album-equivalent unit for certification purposes, and certification therefore no longer reflects shipment alone. For example, in the update of the certification for Their Greatest Hits (1971–1975) by the Eagles in August 2018, the album was certified 38× Platinum (increasing from the previous 29× Platinum certification in 2006) based on the new criteria, making it then the album with the highest certification in the United States.