SUNRAYSIA people separated from friends and family in South Australia will be able to move freely between states from November 23, provided they are fully vaccinated against COVID.

South Australian Premier Steven Marshall has announced that the state's borders will open on that date, which is expected to approximately coincide with that state reaching a vaccination rate of 80 per cent.

Unvaccinated people and anyone from a local government area with a vaccination rate below 80 per cent, however, will remain subject to current border restrictions.

South Australia will also cut quarantine times for fully vaccinated international travellers from 14 days to seven.

It is planning to drop almost all of its COVID restrictions once the state hits a full-vaccination mark of 90 per cent, which is expected by the end of the year.