D12, an initialism for The Dirty Dozen, is an American hip hop group from Detroit, Michigan.

D12 has had chart-topping albums in the United States, United Kingdom, and Australia.

D12 was formed in 1996, and achieved mainstream success after Eminem rose to international fame. D12 released the album Devil’s Night in 2001 and D12 World in 2004, spawning numerous hits such as “Fight Music”, “Purple Pills”, “My Band”, “How Come” and “Shit on You” throughout that period.

Since 2006, Eminem’s hiatus and the death of the member Proof resulted in them being less active in subsequent years.

On May 21, 2008, after four years of inactivity and the passing of Proof, D12 released a new mixtape, Return of the Dozen Vol. 1. The mixtape was designed to get D12 back on their feet in preparation for new possible content. The mixtape lacked Eminem (who was working on his solo album, Relapse). It contains several guest features from rappers such as Royce da 5'9" (whom they had a feud with) and King Gordy. Some tracks were solo performances from a D12 member, such as "If You Want It" by Kuniva, in a similar way to how Eminem performed "Girls" from Devil's Night.

D12 released their mixtape Return of the Dozen Vol. 2 on April 12, 2011, which featured Fuzz Scoota. Fuzz Scoota was one of the original members of D12 but left in 1999. He then later joined back with D12 on April 7, 2011. Eminem was only present on one track throughout the whole mixtape, though he wasn't present at all in the previous one. Due to Eminem being on tour for his album Recovery and because of Mr. Porter being his current hype man there were four active members of D12 at the time (Bizarre, Kuniva, Fuzz and Swift). The others, while not currently active, were still members of D12. In a video posted on YouTube by Eminem & Royce da 5'9" on June 13, 2011, Eminem stated that he was back in the studio with D12 after not being a very active member for nearly three years. D12 performed at the Kanrocksas Music Festival on August 5, 2011.

The track, "Outro", off the Return of the Dozen Vol. 2 mixtape, had a music video released on September 1, 2011, though the video did not feature either Eminem or Mr. Porter. The group also stated intentions to celebrate the 10th anniversary of the release of the Devils Night album, though the celebration was held on the actual Devil's Night on October 30 in Saint Andrew's Hall in Detroit, Michigan, even though the album was released months earlier on June 19, 2001.

In 2012, Bizarre left the group, citing creative differences. That same year, Mr. Porter announced that he had left D12 via a series of tweets. In the Twitter posts, he said that he wanted to focus on being a solo artist, but clarified that holds no animosity toward other members of the group. The group now currently has only four members.