Lost island

Lost island may refer to:


 * Federal Republic of Lostisland, a global sovereign entity and a social and cultural organization
 * Lost Islands (film), a 2008 Israeli film
 * Lost Island Theme Park, in Waterloo, Iowa
 * Lost Island Township, Palo Alto County, Iowa
 * a lost continent or island, see List of lost lands
 * the fictional island of the television series Lost, see
 * "Lost Island" refutation, the response by Gaunilo of Marmoutiers to Anselm's logical proof of the existence of God