The number of countries on the UK Covid travel red list will be cut from 54 to seven, the government says.
South Africa, Brazil and Mexico come off the red list, which requires travellers to quarantine in an approved hotel at their cost for 10 full days.
Transport Secretary Grant Shapps said the changes begin on Monday and “mark the next step” in opening travel.
This latest move will be seen as a boost to the airline industry and families separated during the pandemic.
Panama, Colombia, Venezuela, Peru, Ecuador, Haiti and the Dominican Republic remain on the red list.
Pandemic travel rules in the UK have recently been simplified, with the amber list cut, and advice against holidays changed for 32 countries.
But consumer group Which? warned the changes only reflect requirements for arriving back in the UK.
“Travellers should be aware that they may still face restrictions on entry to many destinations, especially those under 18 who are not yet vaccinated,” it said.
Arrivals from 37 more destinations will have their vaccination status certificates recognised, meaning they can avoid more expensive post-arrival testing requirements.
Vaccinated travellers from Brazil, Hong Kong, India, Pakistan, South Africa and Turkey will be treated the same as returning fully-vaccinated UK residents so long as they have not visited a red-list country in the 10 days before arriving in England.
All arrivals will still complete a passenger locator form.
The Scottish government said the changes were “agreed on a four-nation basis”.
The Welsh government said that they increased opportunities for new infections and variants, but it was adopting them because it was not practical to have its own border policy.
Announcing the latest changes, Mr Shapps said the government was “making it easier for families and loved ones to reunite”.
He said that with fewer restrictions “and more people travelling, we can all continue to move safely forward together along our pathway to recovery”.
In addition to the shorter red list, the government said passengers would soon be able to use a photograph of a lateral flow test as a minimum requirement to verify a negative result.
This change – affecting tests taken by eligible fully-vaccinated people from non-red list countries two days after arrival in England – would come into effect in “late October”, the Department for Transport (DfT) said.