11 countries have been removed from the UK's travel red list.
Angola, Botswana, Eswatini, Lesotho, Malawi, Mozambique, Namibia, Nigeria, South Africa, Zambia and Zimbabwe were on the list.
The red list was reintroduced in late November as a precaution after the emergence of the Omicron variant.
However, Health Secretary Sajid Javid said it had spread so widely the rules no longer had much purpose.
"Now that there is community transmission of Omicron in the UK and Omicron has spread so widely across the world, the travel red list is now less effective in slowing the incursion of Omicron from abroad," he told Parliament.
"Whilst we will maintain our temporary testing measures for international travel we will be removing all 11 countries from the travel red list effective from 4am tomorrow morning."
All UK arrivals from red list countries are required to pay for and self-isolate in a pre-booked, government-approved hotel for 10 days.
But with all 11 countries being removed from that list, it was confirmed that those currently in managed quarantine would be allowed to leave early and "follow the rules as if they had arrived from a non-red list country".
Some travellers had paid thousands of pounds to stay in government-approved quarantine hotels, with complaints of chaotic organisation and inedible food during their stays.
Anyone who has tested positive will to remain in isolation, the Chancellor of the Duchy of Lancaster Stephen Barclay told the House of Commons.
Mr Javid also said earlier he was "very persuaded" by calls to reimburse people and hoped to make an announcement on that soon.
The move follows anger from African countries, with the UN describing the ban on non-UK residents entering England as "travel apartheid".
South African Tourism Minister Lindiwe Sisulu said the UK announcement had "come just in time to allow families and friends to unite over the festive season".
The travel industry had also warned the restrictions were hurting business.
Tim Alderslade, head of trade group Airlines UK, said emptying the red list made "complete sense" but that the government should also scrap the remaining travel restrictions.
"If the red list isn't necessary given that Omicron is established here at home, then neither are the costly emergency testing and isolation measures imposed on even fully vaccinated travellers," he added.
Currently all arrivals, regardless of where they fly from, must take Covid tests within 48 hours of setting off for the UK and PCR tests within two days of their arrival.
ABTA, which represents the travel industry, called the red list removals "a sensible step" but also urged the government to remove the temporary testing requirements and to come up with a plan for the sector for future variants, including transition arrangements for the red list so people overseas when that country is placed on the list can quarantine at home in the UK.
The red list was designed to halt variants entering the UK, but modelling from the UK Health Security Agency (UKHSA) shows Omicron is currently infecting 200,000 people a day in the UK.
Mr Javid said on Monday the variant now represents more than 20% of cases in England.