The 26-year-old student had returned from Saudi Arabia, and tested positive while in state quarantine. The man is being treated in Naradhiwas Rajanagarindra Hospital.
The patient had flown to Malaysia and taken the bus to Thailand through the Padang Besar checkpoint in Songkhla province.
Other people who travelled in the same bus are being checked for infection, the spokeswoman added.
The total number of confirmed cases since the outbreak increased to 3,077, of whom 59 are still being treated in hospitals. The number of fatalities remains at 57.
The number of people in state quarantine is 20,953 of whom 140 have been found to be infected, she said.
Meanwhile, globally the number of new cases surged by 125,608 within 24 hours, the highest single-day rise since the outbreak, of whom 25,069 were in the US where the total cases rose to around 1.8 million
In Asia, India had the highest number of cases totalling 173,791, including 8,105 new cases. India now has the seventh highest number of cases in the world. Panprapa said Thailand was stable at 77th in the world.