"What You Know" is a song by American rapper T.I., released as the lead single from his fourth studio album King (2006).

The song peaked at number three on the Billboard Hot 100 and was certified double platinum by the RIAA following shipment in excess of two million copies.

It utilizes an interpolation of Roberta Flack's version of The Impressions's "Gone Away" and of the song "Hey Joe", written by Billy Roberts but popularized by Jimi Hendrix.

On December 14, 2006, the song was certified double platinum by the Recording Industry Association of America (RIAA) for sales of over two million copies in the United States.

[4] American rappers Juelz Santana and J.R Writer, of Dipset, recorded a remix of this song entitled "What You Know (About That Crack)".