Rainbow is the seventh studio album by American R&B singer Mariah Carey, released on November 2, 1999, by Columbia Records. The album followed the same pattern as Carey's previous two albums, Daydream (1995) and Butterfly (1997), in which she began her transition into the urban adult contemporary market. Rainbow contains a mix of hip hop-influenced R&B tracks, as well as a variety of ballads. Carey produced the album with David Foster and Diane Warren, who, as well as Jimmy Jam & Terry Lewis, replaced Walter Afanasieff, the main balladeer Carey worked with throughout the 1990s. As a result of her separation from her husband, Tommy Mottola, Carey had more control over the musical style of this album, so she collaborated with several Hip-Hop artists and rappers such as Jay-Z, Usher and Snoop Dogg, as well as Missy Elliott, Joe, Da Brat, Master P, 98 Degrees and Mystikal.

On Carey's previous album, Butterfly, she began incorporating several other genres, including R&B and hip hop, into her musical repertoire. In order to further push her musical horizons, Carey featured Jay-Z on the album's lead single, the first time in her career that another artist was featured on one of her lead singles. Carey wrote ballads that were closer to R&B than pop for this album, and worked with Snoop Dogg and Usher on songs such as "Crybaby" and "How Much", respectively, both of which featured strong R&B beats and grooves. Several of the ballads that Carey wrote during this period, including "Thank God I Found You" (written with Terry Lewis) and "After Tonight" (written with Diane Warren), mirrored sentiments she experienced in her personal life.

The album spawned five singles, two of which became number-one hits on the US Billboard Hot 100, making Rainbow her seventh-consecutive studio album to produce one or more number-one hits. The album's lead single, "Heartbreaker", became Carey's fourteenth number-one hit on the Billboard Hot 100 and topped the record charts in Canada and New Zealand. "Thank God I Found You", featuring Joe and 98 Degrees, also topped the Billboard Hot 100, but achieved moderate international chart success. The next two singles, "Can't Take That Away (Mariah's Theme) and "Crybaby" featuring Snoop Dogg, were released as a double A-side. The songs were at the center of a public feud in between Carey and Sony Music due to the label's alleged weak promotion of the singles. Carey's cover of Phil Collins' "Against All Odds (Take a Look at Me Now)" with Westlife peaked at number one in Ireland, Scotland and the UK Singles Chart.

Rainbow was well received by music critics, who generally praised Carey's embrace of R&B and hip hop in her music. The album debuted at number two on the US Billboard 200, with first week sales of 323,000. It was her first album in years to not reach number one. However, within a month, Rainbow was certified triple-Platinum by the Recording Industry Association of America (RIAA), denoting shipments of three million copies within the United States. Internationally, the album peaked at number one in France and Greece, and charted within the top-five positions in Australia, Austria, Belgium, the Netherlands, Germany, Japan and Switzerland. Globally, Rainbow has sold an estimated eight million copies.