France and the Netherlands are among a list of countries added to the UK quarantine list.
Travellers from France, the Netherlands, Monaco, Malta, Turks & Caicos & Aruba, who arrive in the UK after 4am on Saturday, must self-isolate for 14 days.
UK transport secretary Grant Shapps made the announcement on Thursday.
It comes amid fears over rising numbers of coronavirus cases in the affected areas.
The latest 14-day cumulative figures show 32.1 Covid-19 cases per 100,000 people in France, compared with 18.5 in the UK.
With Spain already on the quarantine list, it now means that holidaymakers returning to the UK from the two most popular overseas destinations must now immediately self-isolate.
Prime Minister Boris Johnson said ministers would be “absolutely ruthless” in deciding on whether to impose the self-isolation requirement.
First Minister Nicola Sturgeon has also warned against booking holidays as the list is subject to constant change.
Anyone caught breaking the restriction could face a fine of £480.