#1's is the eighth album by American pop-R&B singer Mariah Carey, released by Columbia Records in Europe on November 16, 1998 (see 1998 in music). Carey's first compilation album, it comprises her first thirteen number-one singles on the U.S. Billboard Hot 100 chart and several new tracks. It was certified five-times platinum in the U.S. after debuting within the top five on the Billboard 200, and it charted strongly elsewhere. Sales of #1's were higher than expected, and its commercial success has been credited with influencing the content of later greatest hits albums by other acts.
Carey has said that she does not consider #1's a greatest hits album, and she has voiced her disappointment with the omission of what she calls her "favorite songs". Reviews were mixed, with criticism directed towards both the new material and the decision to include only Carey's number-one hits. The singles released from the album — "Sweetheart" with Jermaine Dupri, the award-winning Whitney Houston duet "When You Believe" from the soundtrack to The Prince of Egypt, and "I Still Believe" — sold well across the world, but they were only moderately popular on U.S. radio.