Slipknot is the eponymous debut studio album by the American heavy metal band Slipknot. It was released on June 29, 1999 by Roadrunner Records, following a demo containing a few of the songs which had previously been released in 1998. Later, it was reissued in December 1999 with a slightly-altered track listing and mastering as the result of a lawsuit. It was the first release by the band to be produced by Ross Robinson, who sought to refine Slipknot's sound rather than alter the group's musical direction. This is the only album to feature original guitarist Josh Brainard who left at the end of recording in late 1998 while the band was back in Iowa for a break. Jim Root, who recorded two tracks at this point, would appear full time on subsequent albums.
The album spans several genres, but is generally noted for its extensive percussion and overall heavy sound. It was well received by fans and critics alike and was responsible for bringing Slipknot a large increase in popularity. The album peaked at number 51 on the Billboard 200, and has gone on to become certified double platinum in the United States, making it the band's best-selling album. In 2011, it was voted the best debut album of the last 25 years by readers of Metal Hammer magazine.