Slip It In is the fourth studio album by the American hardcore punk band Black Flag, released in 1984 by SST Records.

Slip It In is an extension of the sound Black Flag utilized on its second album My War: heavy, cathartic, intense, dense and progressive.

The album pursued the newer, lengthier song arrangements that Black Flag would develop until its demise.

In many ways, Slip It In is a fusion of the styles utilized on their previous releases (with vocals), Damaged and My War.

At the middle point of the album, there is an instrumental track called "Obliteration" which highlights Ginn's chord progressions where Brandon Sideleau of Punknews.org claims that it "mashes sludge and jazz into an ominous hybrid."

He defends the title track, calling it a "punk metal masterpiece often unfairly seen as sexist, when in reality it's quite the opposite.