The state government says construction of Goolwa Secondary College should be finished by Christmas this year.
In an update about the state's four new schools, Minister for Education John Gardner said building at the Goolwa site was well underway.
"Local families are rightly excited about the delivery of the schools which will provide outstanding learning environments for generations to come," he said.
"I'm looking forward to seeing these spaces comes to life with the first intake of students who I'm sure will be thrilled to learn in the state-of-the-art facilities."
The school is set to open with progressive enrolments, starting with year sevens and eights in term one next year.