Avantasia is a German symphonic/progressive power metal supergroup project created by Tobias Sammet, vocalist of the band Edguy. It has been characterised as a rock opera, featuring the participation of various vocalists and musicians. The name is a portmanteau of the words "avalon" and "fantasia" ("fantasy") and describes "a world beyond human imagination" (a quotation from the booklet).

The project can be divided into three periods of activity. The first, 1999-2002, saw the release of a self-titled single and two full-length albums with the subtitle The Metal Opera. The second, 2005-2011, consists of the EPs Lost in Space Part I & II and the The Wicked Trilogy, composed of the albums The Scarecrow, The Wicked Symphony and Angel of Babylon. The third period, 2013-2016 begins with the album The Mystery of Time and ends with the forthcoming release Ghostlights.