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 Slappy portion of the compilation included one cover, "Knowledge", which was originally by influential California punk band Operation Ivy, whose singer, Jesse Michaels, contributed the artwork for the album. The cover features the same image from 39/Smooth.
The album was re-released in 2004 with special limited packaging and all new CD-rom features, including live performances and pictures and re-issued in the same packaging in 2007 through Reprise Records after Green Day pulled the album in August 2005, as well as all of its other material released through the label, from Lookout! due to unpaid royalties. According to Nielsen SoundScan, it has sold 632,000 copies in the US as of August 2010. The album was certified Gold in the UK on July 22, 2013 representing sales of at least 100,000.