The prime minister made the announcement in a televised address from Downing Street, on Monday.
The development comes after the UK recorded more than 50,000 new confirmed COVID-19 cases for the seventh day in a row.
UK chief medical officers had recommended the COVID-19 threat level be increased from four to five — its highest level.
The medical officers warned of a “material risk of healthcare services being overwhelmed” in several areas over the next 21 days.
Johnson said the new lockdown, which will remain till mid February, is expected to contain the spread of the new virus variant.
He said residents should only leave their homes for limited reasons, which have been outlined in a 22-page document published by the government.
“In England, we must therefore go into a national lockdown which is tough enough to contain this variant. That means the government is once again instructing you to stay at home,” he said.
“You may only leave home for limited reasons permitted, such as to shop for accessories, to work if you cannot work from home, to exercise, to seek medical assistance such as getting your COVID test or to escape domestic abuse.”
Johnson said the new COVID-19 strain is spreading at a “frustrating and alarming” rate, adding that “you are much, much more likely to catch the virus and pass it on”.
He added that UK hospitals “are under more pressure from COVID than at any time since the start of the pandemic”.
A new variant of the coronavirus was first identified in Kent and has since spread across the UK and other parts of the world at a faster pace.
More than 40 countries including France and Saudi Arabia have banned international flights to the UK over new strain of COVID-19.
In October, the prime minister had announced a second national lockdown in England to prevent a “medical and moral disaster”.