Brass Knuckles is the fifth studio album by American rapper Nelly, released on September 16, 2008 after several delays. In 2008 Nelly embarked on The Brass Knuckles Tour in support of the album.

Cornell Iral Haynes Jr., better known by his stage name Nelly, is an American rapper, singer and actor. He grew up in St. Louis, Missouri, and embarked on his musical career in 1993 as a member of the Midwest hip hop group St. Lunatics. He signed with Universal Records in 1999 as a solo act to release his debut studio album, Country Grammar (2000) in June of the following year. Its namesake lead single and follow-up, "Ride wit Me" both entered the top ten of the Billboard Hot 100, while the album peaked atop the Billboard 200 and received diamond certification by the Recording Industry Association of America (RIAA). His second album, Nellyville (2002) spawned two consecutive Billboard Hot 100 number-one singles, "Hot in Herre" and "Dilemma", along with the top-five single, "Air Force Ones".