Ad Astra is an annual science fiction fantasy and horror convention in Ontario, Canada. Major events of the convention include the Masquerade, Guest of Honor presentations, panel discussions, Art Show and Dealer's room, as well as a wide variety of privately run room parties. Other events on the convention program includes a games room, book launches and the Saturday evening dance.
Ad Astra first ran in 1980, and has run every year since, excepting 1981 and 1999. The convention occasionally serves as host for other conventions, for example, Canvention 7 was held as part of Ad Astra 7, in 1987 and the convention hosted the Toronto games convention Orion for the yeas 2003 and 2004.