Premier Jay Weatherill, Tourism Minister Leon Bignell and AirAsia X CEO Azran Osman-Rani are expected to announce details of the new services this afternoon.
Council for International Trade and Commerce SA chairman Francis Wong tweeted earlier: "Great news! @Airsia X is coming to #Adelaide in October 2013".
The Kuala Lumpur-based budget carrier currently flies out of Darwin, Sydney, Melbourne, Perth and the Gold Coast.
It reaches destinations including China, Malaysia, Thailand, Indonesia, India, Japan, Singapore and Hong Kong.
Passengers can book extremely cheap flights but must pay in-flight for checked baggage, meals, seat selection and comforts such as pillows and blankets.