Unless the virus is halted, the measures will be in place for six months, Mr Johnson warned.
So what are the new restrictions across England, Wales, Scotland and Northern Ireland, and how do they differ?
New coronavirus measures in England include a curfew on pubs, a tightening of the 'rule of six' and face coverings must be worn in taxis and private hire vehicles, and by retail staff while at work.
The prime minister told MPs people should work from home where possible and the hospitality sector will be restricted to table service only from Thursday.
Mr Johnson also warned it will be a legal requirement for people to follow the new rules and the military could be drafted in to help police enforce them.
He also confirmed the exemptions to the rule of six will be reduced, banning indoor team sport – such as indoor five-a-side football matches.
Wedding ceremonies and receptions in England will be capped at 15 people from Monday, but up to 30 will still be able to attend a funeral.
There will also be no return of spectators to sports venues as originally planned for October 1.
In a statement to the House of Commons, the prime minister said the new rules are likely to be in place for six months unless they result in a swift decline in virus infections.
If significant progress is not made on vaccines, treatments or tests, "we should assume that the restrictions that I have announced will remain in place for perhaps six months," Mr Johnson said.
Household visits will be banned across Scotland from Wednesday, Scotland’s First Minister Nicola Sturgeon announced.
However, there will be exemptions for those living alone, couples not living together, childcare and tradespeople.
Workers in Scotland have been asked to continue to work from home if they can.
The First Minister told employers who have encouraged people back into the office to "rethink that".
She added that if there is non-compliance from employers, then the Scottish Government may impose a “legal duty” on businesses to allow home working.
A 10pm curfew will be also put in place for hospitality businesses, including pubs, restaurants and bars in Scotland.
People in Scotland are also being advised against car-sharing, with Ms Sturgeon saying that according to Test and Protect data there is a "significant risk of transmission" in such settings.
She said no decision has been taken yet on a so-called circuit-break in October, and the Scottish Government is "keeping it under review".
First Minister Mark Drakeford indicated people in Wales could be asked to make essential journeys only.
He said "one of the central dilemmas" the country faced was the differing rates of Covid-19 in different areas, with rates of the virus still falling in 10 local authority areas.
"I will want to say something later today about trying to encourage people in Wales only to make those journeys that are really necessary," he told the Senedd.
Mr Drakeford said many of the things being announced by Mr Johnson "we have already done in Wales", such as the encouragement to work from home where possible.
Measures across much of South Wales came into force at 6pm on Tuesday.
The measures, which are already in force across Rhondda Cynon Taf and Caerphilly county borough, will now apply in Bridgend, Merthyr Tydfil, Newport and Blaenau Gwent.
Under the new rules people must not enter or leave the areas without a reasonable excuse and are only able to meet with other households outdoors, including members of their extended household.
Northern Ireland has the highest infection rate across the UK and Ireland, and fresh Covid-19 restrictions are to be extended from some specific postcodes to the whole country from 6pm on Tuesday.
Households will no longer be allowed to mix indoors, except for single-person bubbles and certain other exemptions.
No more than six people from two households can meet in a garden.
Pubs which do not serve food, known as wet pubs, are due to open on Wednesday, despite the latest restrictions.
Deputy First Minister Michelle O’Neill said whether to introduce an early closing time for pubs is something ministers would be considering, describing replicating the 10pm curfew being introduced in England as "fair enough" to consider.
First Minister Arlene Foster said a two-week period of lockdown to try to halt the spread of the virus, a so-called circuit breaker, could not be ruled out.