Operation Ivy was an American punk rock band formed in Berkeley, California, in the late 1980s around Jesse Michaels, Tim Armstrong, Matt Freeman and Dave Mello. Their music blended hardcore punk, ska and reggae, with fast, melodic and socially conscious songs that helped define American ska punk. Despite a very short career, with the Hectic EP and the album Energy, Operation Ivy became one of the most influential bands in California’s independent punk scene.