The premier said a two-week lockdown is needed in order to contain community transmission of the highly-contagious Delta variant.
"When you have a contagious variant like the Delta virus, there's no point doing a three-day lockdown and having the virus bubble away in the community," she said on Saturday.
The restrictions for Greater Sydney will remain in place until at least midnight on 9 July. Ms Berejiklian said health authorities will assess the situation after seven days, but that "this will be, for all intents and purposes, a two-week lockdown".
Here's what the new restrictions mean for you.
Stay-at-home orders for Greater Sydney
From 11.59pm on Saturday, everyone in Greater Sydney will only be able to leave their homes for essential reasons. These include:
- Shopping for food or other essential goods and services;
- Medical care or compassionate needs, including people who have a COVID-19 vaccination (unless you have been identified as a close contact);
- Exercise outdoors in groups of 10 or fewer;
- Essential work or education, where you cannot work or study from home;
- Childcare access, or accessing a parent or child, or to provide assistance to a vulnerable person;
- For compassionate reasons, including where two people are in a relationship but do not necessarily live together;
- Accessing social services, employment services, domestic violence services, mental health services and police;
- Moving home.
Changes to weddings, funerals and community sport
Weddings can go ahead this weekend, but will not be permitted from Monday, 28 June, until the end of the lockdown.
Funerals will be limited to one person per square metres with a cap of 100 people, and masks must be worn indoors.
Community sport will not be allowed during this period.
What about the rest of NSW?
Anyone who has been in Greater Sydney, including the Blue Mountains, Central Coast and Wollongong, on or after 21 June are being asked to follow the stay-at-home-orders for 14 days after leaving the region.
People across NSW should only enter Greater Sydney for essential purposes. This includes returning to your home.
A range of restrictions will also be re-introduced for regional NSW.
Residents of Greater Sydney must comply with stay-at-home rules.
Across the rest of NSW, visitors to households will be limited to five guests, including children.
Face masks compulsory
Masks will be compulsory in all indoor non-residential settings, including workplaces and at organised outdoor events across all of NSW.
Non-essential venues and services to close across Greater Sydney
Pubs and clubs, and food and drinks venues can open for takeaway only. Entertainment facilities such as theatres, cinemas, amusement arcades, casinos and nightclubs will close.
Gyms, public swimming pools and other indoor recreation facilities will also close (though ocean polls will remain open).
Places of worship will close, except for the purpose of conducting a wedding or funeral.
Hairdressers, massage salons and nail and beauty salons will also close.
Outside of the Greater Sydney lockdown region, dance and gym classes will be limited to 20 per class, and masks must be worn.
Real estate auctions and open inspections
Auctions that people attend in person and open inspections of properties will not be permitted, although inspections may be conducted by private appointment for one person only.
Interstate and trans-Tasman travel
All states and territories have introduced travel restrictions in response to the Sydney outbreak.
Earlier this week, Victoria declared all of Greater Sydney, including the Central Coast, Blue Mountains, Shellharbour and Wollongong, red zones under their travel permit system from 1am on Friday, barring people who have recently been in the areas from travelling without an exemption.
Travellers from NSW COVID-19 hot spots wanting to cross into Victoria have been sent a stark warning.
"The message is simple. Don't come from a NSW red zone to Victoria. To Victorians, do not visit those red zones in NSW," Victorian Health Minister Martin Foley said on Saturday.
Queensland has applied similar rules to people in Greater Sydney, the Central Coast, Blue Mountains, Wollongong and Shellharbour, while South Australia has introduced a travel ban for anyone who has been in NSW since 11 June (barring border communities).
Western Australia has also closed its border to travellers from NSW.
Authorities in the ACT extended stay-at-home order to apply to travellers from whole of Greater Sydney, not just metropolitan Sydney.
Those who have returned to ACT since 21 June from Greater Sydney - including the NSW Central Coast, Wollongong, and the Blue Mountains - are now subject to stay-at-home orders for the next fortnight until 9 July.
The Northern Territory has declared Greater Sydney a hot spot, forcing arrivals from these areas to undergo a 14-day supervised quarantine, and Tasmania has banned travellers from high-risk local government areas from entering the state without an exemption.
New Zealand has also suspended the trans-Tasman bubble arrangement in response to the recent outbreak.