Travellers to Wales from Hungary will have to self-isolate for 14 days on arrival from Saturday, but Sweden is to be removed from the quarantine list.
Hungary and the French island of Reunion in the Indian Ocean join countries like France, Spain and Portugal on Wales' quarantine list.
The new rules will come into force at 04:00 BST on Saturday and will also apply to those returning to England.
Ten Greek islands, Austria and Belgium are also on Wales' quarantine list.
A similar announcement was made by the UK government for England, which also decided to remove mainland Portugal, French Polynesia from its quarantine list.
The countries had already been added to Wales' quarantine list.
Health Minister Vaughan Gething said he made the decision to make the changes following a review of the latest assessments by the Joint Biosecurity Centre.