Carey took to Instagram to share a Flashback Friday post, honouring the "I Will Always Love You" star with a vintage snap of the pair, reported People magazine.
The photo was taken in 1998 when the pop stars performed the duet "When You Believe", for the DreamWorks animated film "The Prince of Egypt".
Houston died in 2012 having accidentally drowned in the bathtub of her Beverly Hilton Hotel room. Contributing factors to her death included cocaine use and heart disease.
Upon hearing the news, a devastated Carey took to Twitter to remember Houston. The singer said she was "heartbroken and in tears" and added, "She will never be forgotten as one of the greatest voices to ever grace the earth.