Deborah Cox (born January 7, 1974 in Toronto, Ontario) is a Canadian R&B/pop singer, whose 1999 smash hit "Nobody's Supposed to be Here" was the longest-running number one single in the history of Billboard magazine's R&B charts.

She got into the music industry as a backup vocalist for Céline Dion, and after signing to Arista Records, released her self-titled debut album in 1994. The album made her a rising star, and set the stage for 1998's One Wish. The first single from that album, "Nobody's Supposed to be Here", spent a record 14 weeks atop the Billboard R&B charts.

On February 17, 2004, Cox made her Broadway debut in the Elton John-Tim Rice musical Aida . Her third album, The Morning After, was released in November, 2002.