From July 1 travellers arriving by air must be fully vaccinated or test negative for Covid-19 to enter the country immediately, according to the Civil Aviation Authority of Thailand.
CAAT said in a statement on Monday that it had informed airlines of the new arrival conditions, which take effect on Friday.
It said the country would lift its requirement for arrivals to register their inbound travel using the Thailand Pass system prior to departure.
Fully vaccinated air passengers could enter without having to show a Covid-19 test result. If they were sick, they should use a rapid antigen test.
Unvaccinated and inadequately vaccinated people must test negative for Covid-19 no more than 72 hours before their arrival, so they could enter the country immediately.
Otherwise, travellers must follow the orders of disease control officials.
CAAT said it advised air passengers to continue wearing face masks while aboard their planes, because cabins were enclosed areas.