The more than 100 partygoers caught breaking Covid-19 restrictions at a Koh Phangan bar were fined 4,000 baht each.
They were also each sentenced to one month in prison, suspended for one year.
The bar owner and a staff member were each fined 10,000 baht and sentenced to two years in prison, suspended for one year.
A total of 109 customers were detained - 89 foreigners (38 men and 51 women) and 20 Thais (7 men and 13 women) - when immigration and tourist police and local officials raided the Three Sixty Bar in Koh Phangan district on Tuesday night.
Forty bottles of beer and whisky and a notepad were seized.
A Russian man said he was at the party because he thought nothing would happen. He apologised to the Thai people.
