Granite Island Recreation Park will be closed at night for the 19th consecutive year throughout Schoolies Week from Friday, November 22 to Wednesday, November 27.
Closures will be in place from 10.30pm to 5.30am each night over this period when large numbers of school leavers visit Victor Harbor.
Paul Unsworth from National Parks and Wildlife Service SA said the closures were in place to protect the community and the island's wildlife.
"Visitors are able to visit the island as normal during the day, from very early in the morning," Mr Unsworth said.
While the island will be closed to the general public, the closure will not apply to anyone fishing on the causeway or screw pile jetty.
Employees of Oceanic Victor, the island lessee, will also be allowed to access the island while undertaking their normal work duties.
Mr Unsworth said National Parks and Wildlife Service SA was grateful for the Victor Harbor community's ongoing support, especially at this time of the year.
For more information contact 8552 0300.
The Granite Island Causeway was also closed on Thursday morning as the Department of Planning, Transport and Infrastructure investigated the safety of the causeway, after winds exceeding 100km/h hit it on Wednesday, November 20.
It has since reopened to pedestrians, vehicles and the horse drawn tram.