1,039/Smoothed Out Slappy Hours is a collection of early recordings by the American punk rock band Green Day. It was released on July 1, 1991, through Lookout! Records. Often referred to as the band's debut album, the compilation combines the band's actual debut 39/Smooth and its first two extended plays Slappy and 1,000 Hours, which are all currently out of print. The album included one cover, "Knowledge" (originally from the Slappy EP), which was originally by influential California punk band Operation Ivy, whose singer, Jesse Michaels, contributed the artwork for the album. The cover art features the same image from 39/Smooth.

39/Smooth is the debut studio album by the American punk rock band Green Day. It was released on April 13, 1990 through Lookout Records on vinyl (black and green) and cassette. It is the band's only studio album to feature John Kiffmeyer on drums.