South Australia will open hundreds of new prison beds as part of a record $227 million state government plan.
Thursday's state budget will include more than $205 million to create another 312 high-security beds at Yatala Labour Prison in Adelaide's north.
The extra beds - to be spread across three separate divisions - would bring the total at the prison to more than 1150, representing a 37 per cent increase in its capacity, Treasurer Stephen Mullighan said on Saturday.
The high-security beds were expected to be available from the end of 2027.
Additionally, $21 million will be put into expanding Adelaide Women's Prison by 40 beds, taking the total number of beds at that facility to 316.
The beds at the women's prison will be in an independent living environment, and construction on them is expected to start in January 2025.
"The Malinauskas government remains committed to building the capacity of our prison system to keep South Australians safe," Mr Mullighan said.
"The expansion of Yatala will confirm its role as the largest high security prison in our state."
Correctional Services Minister Dan Cregan said increasing capacity to improve the rehabilitation process would improve employment and post-release outcomes.
He noted SA had the country's lowest rate of recidivism.
The $227 million spend would be the state's largest ever to increase prisons' capacity, the government said.
