Denmark is among four countries being removed from the Government’s quarantine exemption list, Transport Secretary Grant Shapps said.
Restrictions are also being reimposed on arrivals from Iceland, Slovakia and the Caribbean island of Curacao due to rising coronavirus cases.
The 14-day self-isolation requirement for travellers arriving in the UK from any of those countries comes into force at 4am on Saturday.
The Department for Transport said the decision covers the whole of the UK and has been agreed with the devolved administrations.
No destinations have been added to the Government’s exemption list.
Denmark is currently recording a seven-day rate of 65.2 coronavirus cases per 100,000 people, up from 33.8 a week ago.
A rate of 20 is the threshold above which the Government considers triggering quarantine conditions.
Iceland and Slovakia have rates of 80.4 and 25.9 respectively, while Curacao is on 66.7.
The rate in the UK is 47.3.
Figures have been calculated by the PA news agency based on data collected by the European Centre for Disease Prevention and Control.
The travel industry has been badly hit by quarantine restrictions.
It has called on the Government to allow coronavirus testing at airports to reduce self-isolation periods for those who get a negative result.
Paul Charles, chief executive of travel consultancy The PC Agency, said: “It’s sad to see the list of countries growing on the quarantine list in line with the resurgence of Covid-19 in several parts of the world.
“It now makes even more sense for traveller testing to be introduced as soon as possible, reducing quarantine times and enabling economies to get going again.
“A co-ordinated global programme, combining testing with short quarantine periods if necessary, would help protect lives and livelihoods.”