A leader with Australia's first state-based Voice to Parliament has delivered a historic address decrying continued Indigenous disadvantage, with a call for radical change in how governments interact with First Nations people.

Leeroy Bilney, the presiding officer for South Australia's newly created Voice, spoke to both houses of the South Australian parliament in a joint sitting on Wednesday, marking the first time a Voice model for greater Indigenous representation in political and social affairs has spoken directly to a parliament.

In a speech shot through with hope for a better future for the state's Aboriginal people, Mr Bilney said he, the other elected Voice members and parliamentarians had a "long road ahead" of them to close the persistent gap in welfare between Indigenous and non-Indigenous Australians.

But he expressed confidence a Voice with direct access to the state's decision-makers could transform the status quo and deliver long-term change.

"This historic body is a first for all of us," he said.

"There is no precedent. A member induction guide was created for us, and a code of conduct, but no rule book or procedures beyond the legislation. And there are no examples in Australia that we can look at.

"We had to build all of that from the ground up … we were building the plane and flying it at the same time."

The South Australian Voice gives Indigenous leaders the right to address parliament, cabinet and departmental chiefs on issues that concern Indigenous people.

Premier Peter Malinauskas pledged to legislate a Voice in the run-up to the 2022 election and the Voice was established in 2023 with the First Nations Act. Elections for the body were held in March this year.

There are six regional Voices that together make up the state Voice, with 46 members elected to the body.

The SA Voice is structured to ensure male and female representation on each of the six local Voices.

Of the six regions, five have seven elected members and one, the Central region, has 11 members.

The Central Voice has more members because of its greater Indigenous population.

The six local Voices then select two "joint presiding members" from their own ranks who form a 12-member state Voice that advises the state government directly.

Mr Malinauskas ploughed ahead with the new decision-making process despite the overwhelming defeat of the federal-level Voice referendum in October last year.

Every state in Australia rejected the Voice to Parliament and South Australia recorded a 64 per cent No vote, with all of its federal electorates voting to reject constitutional change.

More to come

Duncan Evans - NCA NewsWire