The legislation has already passed the state's upper house and the vote in the House of Assembly on March 26 is expected to be a formality.
Once passed, Governor Frances Adamson, Premier Peter Malinauskas and Aboriginal Affairs Minister Kyam Maher will proclaim the legislation on the steps of parliament house in front of what is expected to be a large crowd.
Parts of North Terrace will be blocked off, with the proceedings shown on large screens and free public transport provided.
Announcing the special sitting on Friday, Mr Maher said he hoped the passing of the SA legislation would provide some comfort to people around Australia ahead of the referendum on an Indigenous voice to federal parliament.
"It will provide some comfort that no harm can come of this," he said.
"The worst thing that can happen with our voice to parliament and a federal voice to parliament is that Aboriginal people's voices will be better heard.
"There is nothing to lose and everything to gain from an Aboriginal voice to parliament."
The SA legislation proposes regions with directly elected representatives be established around South Australia.
Two members from each group would then form the State First Nations Voice, which could address either house of state parliament on particular legislation of interest to Aboriginal people.
Federal Minister for Indigenous Australians Linda Burney said the federal process towards the referendum and the question to be put to the Australian people had been informed by the South Australian experience, including lessons on how a voice would sit with other legislation.
"It has been very instructive and useful," Ms Burney said.
"I"m not saying that we're going to mirror everything, but what I'm saying is it's been really helpful to listen to what the South Australian model is.
"But most importantly, that it's actually about to happen and it's there to complement and support the work that we're doing federally."
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