Steiner has become a cult figure in the sport off the back of his portrayal on Drive to Survive.
The Italian headed Haas from inception until recently when team owner Gene Haas opted not to renew his contract.
Steiner had expressed an interest in attending the March 16-17 event but his busy F1 schedule was set to prevent his attendance.
However, with no such responsibilities at the moment, he has now been confirmed.
This year’s event falls on the weekend between the Saudi Arabian and Australian Grands Prix.
“People reference us as the Goodwood of the Southern Hemisphere,” event boss Tim Possingham told Speedcafe.
“And that’s a good way of describing it to people that have been to Goodwood Festival of Speed – it’s not like the Revival.
“And it’s flattering that people draw parallels between the two events.”
Possingham would not be drawn on precise details of Steiner’s role or participation in the event, with further details set to be announced at a later date.
Interest in, and awareness of, the Adelaide Motorsport Festival has risen sharply since last year with a number of F1 figures interested in attending.
Steiner joins Sauber driver Valtteri Bottas, who is set to return after first attending the festival last year, and Sky F1 commentator David Croft.
Further high profile announcements are expected to be made in the lead-up to the event.
A number of F1 machines have already been confirmed for this year’s festival, including a Benetton B190 as driven to victory on the streets of Adelaide by Nelson Piquet in 1990.
Organisers have previously confirmed Supercars legend Craig Lowndes will drive an Arrows A10B at the event, while an Arrows A1B will also be present.
More modern machinery will also be in action, with a Benetton B200 from the 2000 F1 season set to blast its way around the Parklands section of the Adelaide circuit.