From 1 October 2021, the following quarantine period applies for entry into Thailand:

A quarantine period of 7 days for international travellers who have been fully vaccinated with vaccines approved by the Thai authorities.
*Travellers must be fully vaccinated at least 14 days prior to their departure date.
A quarantine period of 10 days for unvaccinated international travellers and travellers who are not fully vaccinated.
A quarantine period of 10 days is required for unvaccinated children. If travelling with a fully vaccinated parent, the parent must also quarantine for 10 days.