The second season of the American serial drama television series Lost commenced airing in the United States and Canada on September 21, 2005, and concluded on May 24, 2006. The second season continues the stories of a group of over forty people who have been stranded on a remote island in the south Pacific, after their airplane crashed forty-four days prior to the beginning of the season. The producers have stated that as the first season is about introducing the survivors, the second season is about a 1970s scientific Dharma Initiative research station which the survivors discovered on the island and refer to as "The Hatch". The second season aired Wednesdays at 9:00 pm in the United States. In addition to the regular twenty-four episodes, three clip-shows recapped previous events on the show. "Destination Lost" aired before the premiere, "Lost: Revelation" aired before the tenth episode and "Lost: Reckoning" aired before the twentieth episode. The season was released on DVD as a seven disc boxed set under the title of Lost: The Complete Second Season – The Extended Experience on September 5, 2006, by Buena Vista Home Entertainment.

The Dharma Initiative, also written DHARMA, is a fictional research project and organization featured in the television series Lost. It was introduced in the second season episode "Orientation". In 2008, the Dharma Initiative website was launched. Dharma's interests were directly connected with fringe science. Dharma is a Sanskrit term used in Hinduism, Buddhism, Jainism, and Sikhism. The logo is an octagon with the word "dharma" inside, all inscribed inside a bagua.