The Barngarla people will formally take ownership of large parts of Eyre Peninsula after a successful native title claim that was first lodged in 1996.
Their traditional ownership of the land will come into effect at a ceremony in Whyalla on Wednesday, with South Australian Premier Steven Marshall attending the event.
The premier said the granting of native title had been a long process for the traditional owners and praised their patience and perseverance.
"The claim was first lodged with the National Native Title Tribunal in 1996, and more than two years later it came before the Federal Court, with judgment not given for another 17 years," he said.
"I congratulate the Barngarla people because, despite their challenges, they were patient and persevered to secure the recognition that they have always known to be theirs, that this is their land."
Mr Marshall also used the event to commit his government to do more to overcome indigenous disadvantage.
"I want to ensure an across government focus on the actions we can take together to encourage greater Aboriginal economic participation and improve the delivery of key services," he said.
"I'm not one to pretend that government can solve all problems, but I do believe we can do much better in providing some achievable and measurable outcomes for our Aboriginal communities."
The Barngarla claim covers about 44,500 square kilometres and includes the cities of Port Augusta, Port Lincoln and Whyalla.
About 50,000 people live within its boundaries, making it one of SA's most populated native title areas.