The government on Wednesday reported one new case of coronavirus disease, a returnee from the Philippines already in quarantine.
The country had now been free of local Covid-19 infection for 30 days.
The new case is a man aged 31 who worked at a restaurant in the Philippines. He returned on June 17 and was quarantined in Bangkok. He tested positive for the disease on Monday, but showed no symptoms.
"Lately, most patients have shown no symptoms," a spokesman said.
So far 967 Thais have returned from the Philippines; two of them contracted Covid-19.
The total number of cases is now 3,157, of whom 3,026 have recovered, including three discharged in the previous 24 hours. The death toll remained unchanged at 58.
Global Covid-19 cases rose by as many as 165,878 over the 24 hours to 9.35 million, and the death toll was up by 5,467 to 479,806.
The United States had the most cases at 2.42 million and the most deaths at 123,473. Thailand ranked 93rd by the total number of cases.
