"Knock You Down" is a song by American singer and songwriter Keri Hilson, recorded for her debut album, In a Perfect World.... The song features guest vocals from Ne-Yo and Kanye West. All three artists co-wrote the song with its producer Nate "Danja" Hills, as well as Kevin Cossom and Marcella Araica. The song was released first released to rhythmic and urban airplay in the United States as the album's fourth single in the US, and it would later serve as the third worldwide single.

Keri Lynn Hilson is an American singer and songwriter. Born and raised in Decatur, Georgia, she began her musical career as a songwriter and backing vocalist for other artists under the wing of record producer Anthony Dent in 2002. At the age of 14, Hilson secured a record deal with the girl group D'Signe, which ultimately disbanded. She attended at Oxford College of Emory University while contributing to material for popular artists, including Britney Spears, Usher, Ciara, The Pussycat Dolls, and Mary J. Blige; she joined the songwriting-production group, the Clutch in 2004.