Now That's What I Call Music! 9 was released on March 19, 2002. The album is the ninth edition of the (U.S.) Now series. It peaked at number 3 on the Billboard 200 and has been certified 2x Platinum by the RIAA. The compilation includes one song which reached the Billboard Hot 100: "Family Affair".
The cover is inspired by the NOW 40 UK cover released in 1998 with a different color scheme.
The version of "Get the Party Started" is a remix by Rockwilder using elements of the Eurythmics song "Sweet Dreams (are Made of This)" and featuring rapper Redman, instead of the much more popular original version which was a hit in the United States (and continues to be popular and air on mainstream radio stations to this day).
The album version of "Ain't It Funny" is included, despite not being released as a single in the United States. The "Murder Remix" featuring Ja Rule is the version of the song released as a single (and subsequently reaching number one on the Billboard Hot 100) in the US.
The version of the Trackmasters remix of "Caramel" removes the third verse and goes straight from Ortiz's second verse to Eve's rap.
The album version of "Turn Off the Light" by Nelly Furtado is included over the popular remix featuring Ms. Jade and Timbaland.