People will still be able to leave their homes for essential reasons such as to seek medical care, buy food or collect a social grant.
All shops and businesses will be closed, with the exemption of pharmacies, laboratories, banks, the JSE, supermarkets, petrol stations and health care providers.
Health workers, emergency personnel and security services will continue to work, while soldiers have been deployed to patrol the streets in support of the police.
At midnight on Thursday, several people were arrested in Johannesburg for allegedly disregarding lockdown rules.
Among those arrested were a club owner who continued to operate after midnight despite calls from police minister Bheki Cele for taverns, clubs, pubs and other liquor outlets to remain closed.