The Rainbow World Tour was the fourth concert tour in 2000 by American singer-songwriter Mariah Carey, and supports her seventh studio album Rainbow (1999). The tour started in Europe on February 14, in Antwerp, Belgium, also an itinerary that included North America and ended on April 18, in Toronto. The tour's nine-date North American leg grossed $7.1 million according to Billboard.

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 such as Jay-Z, Snoop Dogg, Master P and Mystikal as well as female rappers Da Brat and Missy Elliott. Other collaborations include the pop and R&B acts Joe, Usher and boyband 98 Degrees.