D12 (an initialism for the Dirty Dozen) was an American hip hop collective from Detroit, Michigan. Formed in 1995, the group achieved mainstream success with its lineup of de facto leader Eminem, Proof, Bizarre, Mr. Porter, Kuniva and Swifty McVay.

D12 had chart-topping albums in the United States, United Kingdom, and Australia during the early 2000s. The group released the albums Devil's Night in 2001 and D12 World in 2004, spawning numerous hits such as "Shit on You", "Purple Pills", "Fight Music", "My Band" and "How Come" throughout that period. Both albums were certified double platinum by the Recording Industry Association of America (RIAA).

In 2004, the group won the MTV Europe Music Award for Best Hip-Hop Act.

Since 2006, Eminem's hiatus and the death of Proof resulted in the group being less active in subsequent years. Between 2008 and 2015, D12 released three official mixtapes with the core lineup reduced to Bizarre, Kuniva and Swifty McVay, with isolated token appearances by Eminem and some contributions from Mr. Porter and Fuzz Scoota.

On August 31, 2018, Eminem released his tenth studio album Kamikaze, containing a song titled "Stepping Stone", announcing that D12 had officially disbanded.