SkyCity's development is being hailed by the state government as the final piece of the Riverbank Precinct upgrade – which already features the redeveloped Adelaide Oval - and as a show of confidence in South Australia's tourism sector.
As many as 1000 jobs are expected to be created during construction, with 800 positions needed once building is complete.
"This development will transform Adelaide Casino into a truly integrated entertainment precinct for international, interstate and local visitors," Adelaide Casino General Manager Luke Walker said.
Urban Development Minister Stephen Mullighan is adamant no extra financial incentive from the state government was needed to seal the expansion deal, which was first flagged in 2012.
Early building works, as part of the Festival Plaza upgrade, have already begun with full construction to start next year.