iiO (pronounced "eye-oh") was a New York City-based house music act composed of singer-songwriter Nadia Ali and producer Markus Moser. The group gained prominence for its 2001 single "Rapture", which reached number two on the UK Singles Chart and Billboard Hot Dance Club Play chart. Following the success of "Rapture", iiO released several singles and the studio album Poetica in 2005. The album reached number 17 on Billboard's Top Electronic Albums Chart.

The same year, Ali left iiO to pursue a solo career. Meanwhile, Moser continued to release material featuring her on vocals, which included the 2006 single Is It Love? that reached number one on Billboard's Hot Dance Club Play Chart. In 2011, he released the the studio album Exit 110, which again featured Ali on vocals and was announced as the final project of the act.