The announcements prompted fears of a new wave of coronavirus on the European continent.
France, Spain and Sweden detected their first cases of the new coronavirus strain that prompted fresh lockdown measures in Britain and global travel bans, authorities said.
All are linked to recent UK travel.
Sweden became the latest EU country to diagnose a case of the new variant on Saturday, according to a statement of the Swedish public health agency.
Four confirmed cases were found in Madrid for the first time in Spain, the regional government said Saturday. All four had recently arrived from the UK.
A Frenchman living in London arrived in France on December 19 and tested positive for the new variant, French public health authorities said in a statement late on Friday.
He had no symptoms and was isolating in his home in the central city of Tours.
French authorities were tracing the person's contacts and laboratories were analysing tests from several other people who may have the new variant, the statement said.
Denmark, the Netherlands, Italy and Germany as well as other places outside Europe, have also reported cases in the past few days. have also reported cases of the new variant, which British authorities said appears 70% more contagious.
The British announcement on December 19 prompted countries around the world to suspend flights from the UK.
France banned all passengers and cargo from Britain for two days, causing massive traffic problems around the British port of Dover.
France reopened the border but now requires anyone entering from Britain to have a test showing they do not have the new variant.
A second partial lockdown sharply curbed France's infections, but they have been on the rise again over the past two weeks.
On Friday, France reported 20,262 new coronavirus cases and 159 more related deaths in hospitals in the last 24 hours.
France's national vaccination campaign is due to start on Sunday, along with other EU countries.