Keith Farrelle Cozart (born August 15, 1995), better known by his stage name Chief Keef, is an American rapper and record producer. Born and raised in Chicago's South Side, he began his recording career as a teenager and initially garnered regional attention and praise for his mixtapes in the early 2010s. Cozart is often credited with popularizing the hip hop subgenre drill for mainstream audiences, and is considered a progenitor of the genre.

His fifth mixtape, Back from the Dead (2012), spawned the single "I Don't Like" (featuring Lil Reese), which became a local hit and marked his first entry on the Billboard Hot 100. A bidding war between several major labels resulted in Cozart signing with Interscope Records, who commercially re-released the song, along with its follow-up, "Love Sosa", which received quintuple platinum certification by the Recording Industry Association of America (RIAA). Both served as lead singles for his debut studio album, Finally Rich (2012), which was met with moderate critical and commercial response, also serving as his only release on a major label. His following independent studio albums—Bang 3 (2015), Bang 3, Pt. 2 (2015), 4Nem (2021), and Almighty So 2 (2024)—have each entered the Billboard 200. Two of his guest appearances—on the songs "Bean (Kobe)" by Lil Uzi Vert and "All the Parties" by Drake—have peaked within the top 40 of the Billboard Hot 100.

Rolling Stone has credited Cozart with "personif[ying] Chicago drill", while Stereogum referred to him as a "modern rap folk hero".