Police will be able to order people back home in the latest bid to curb the spread of Covid-19.
The move preventing people from leaving home without a reasonable excuse was agreed by Stormont ministers last night along with other new measures.
The advice is to be put into legislation from midnight tomorrow, with additional powers being given to the PSNI to enforce the new 'stay at home' measures.
People will only be allowed to leave home for medical needs, to buy food or to exercise.
Those who cannot work from home will also be allowed leave.
Household mixing will be reduced to just one person from another household or bubble, with indoor and outdoor gatherings cut from 15 people to six.
Up to six people from one household will be allowed meet in a private garden.
The measures will last until February 6 with a review on January 21.
Schools are to engage in remote learning until the mid-term break but there is no clarity on whether exams such as the A-levels and GCSEs will go ahead.
First Minister Arlene Foster said discussions on exams are ongoing with Education Secretary Gavin Williamson, with a decision to be made by Thursday.
Mrs Foster said rising Covid cases and hospital admissions were causing "grave concern".
Childcare and special education schools are to remain open.
Deputy First Minister Michelle O'Neill said the interventions are necessary at this time and a reflection "on how serious the situation is" with the pandemic.
Speaking after last night's Executive meeting, Ms O'Neill warned that Northern Ireland faces a "difficult period ahead".
"The message will be stay at home. This will provide additional powers to the PSNI, for example to be able to return people to their homes when they actually come out for reasons that are not allowed under the reasons that you can actually leave your home," she added.
No decision has been made in relation to Churches but an urgent meeting will be held with faith groups about a move to online services.
Meanwhile, the Department of Health has pledged that all over 80s in Northern Ireland will receive the Oxford-AstraZeneca vaccine this month. Just under 400 doses were deployed in 13 GP surgeries on Monday, the first day of the vaccination scheme.
In addition, 46,043 first doses of the Pfizer/BioNTech vaccine have now been administered to care home residents and staff and health and social care staff.
Since December 8, 9,644 care home residents and 11,260 care home staff have received their first jab.
A total of 25,623 healthcare staff have now received the Pfizer/BioNTech vaccine at seven Trust vaccination centres - more than a third of the workforce.
A Department of Health spokesperson added: "While it's very reassuring to see the vaccine rolling out so efficiently, this does not mean that we can drop our guard. Please continue to follow the basic public health advice about social distancing, reducing contact, wearing face coverings and remembering hand hygiene because we need to all we can to keep ourselves and our loved ones safe."
Separately, the Executive has been urged to work "night and day" to distribute £127m in support to businesses hit by the new coronavirus lockdown.
Non-essential retail has been shut since Christmas Eve and hospitality and leisure firms have been closed since Boxing Day.
But Finance Minister Conor Murphy said a £127m cash boost promised for Northern Ireland by the Chancellor Rishi Sunak yesterday was not new.
He said: "Before Christmas, Treasury confirmed a £200m increase to the amount guaranteed for our Covid-19 response. The £127m is covered within this. Covid-19 continues to present many challenges. I'm encouraging Executive colleagues to ensure the remaining funding we have available gets out urgently to where it's needed."
On Christmas Eve, the UK Government said it was "guaranteeing" an extra £800m in new funding for Scotland, Wales and Northern Ireland to help them support people and businesses through the crisis.
Mr Sunak said that in England, businesses in the retail, hospitality and leisure sectors would receive a one-off grant of up to £9,000. But how the money is spent here will be down to the Executive.
Retail NI chief executive Glyn Roberts said he hoped the Executive "will work night and day to get these grants paid out to independent retailers and other high streets businesses".