Adelaide Casino's $330 million expansion will create jobs and help attract conferences to South Australia, Premier Steven Marshall says.
Hansen Yuncken has been selected to complete the work, which is expected to start next month, creating around 1000 construction jobs and 800 permanent jobs when completed in 2020.
"It's going to create jobs, it's going to grow our economy and, most importantly, I think it's going to give us the better infrastructure to attract interstate and overseas visitors," Mr Marshall told reporters on Monday.
The upgrade will include a 123-room hotel, cafes and a day spa, Adelaide Casino General Manager Luke Walker said.
"It is a monumental occasion for Adelaide Casino and indeed the city that we are going ahead with this expansion," Mr Walker said.
Hansen Yuncken won a competitive tender process for the work and recently completed other works on the University of SA's health facility.
The company has promised to work predominantly with local contractors and suppliers on the 12-storey development.
