"One Sweet Day" is a song by American singer-songwriter Mariah Carey and American vocal group Boyz II Men. The song was released on November 14, 1995, as the second single from the former's fifth studio album, Daydream (1995) by Columbia Records. The artists co-wrote the song with Walter Afanasieff, who co-produced it with Carey. Lyrically, the song speaks about the death of a loved one, how the protagonist took their presence for granted and misses them, and finally about seeing the person in heaven. The artists wrote the song about specific people in their lives, being inspired by sufferers of the AIDS epidemic, which was globally prevalent at the time.

Mariah Carey is an American singer, songwriter, record producer, and actress. An influential figure in popular music, she is known for her five-octave vocal range, melismatic singing style, and signature use of the whistle register. Carey is also credited with influencing vocal styles, merging hip-hop with pop through her collaborations, popularizing remixes, and helping break down racial barriers for multiracial Americans in popular culture. Referred to as the "Songbird Supreme" by Guinness World Records, she was ranked as the fifth greatest singer of all time by Rolling Stone in 2023, and has been dubbed the "Queen of Christmas" for the enduring popularity of her Christmas music, particularly the 1994 song "All I Want for Christmas Is You", which is the best-selling holiday song by a female artist.