Thailand to Puerto Rico visa requirements

Yes, a visa is required. Puerto Rico is a U.S. territory and uses U.S. visa policy. Thailand is not in the U.S. Visa Waiver Program, so Thai ordinary passport holders cannot use ESTA and must obtain a U.S. B-1/B-2 visitor visa before traveling. Puerto Rico is an unincorporated territory of the United States, so the same entry rules apply as for the U.S. mainland. There is no separate "Puerto Rico visa." Because Thailand is not a participant in the U.S. Visa Waiver Program (VWP), Thai passport holders are not eligible for ESTA visa-free entry and must apply for a nonimmigrant visitor visa (B-1 for business / B-2 for tourism) at a U.S. Embassy or Consulate. In Thailand this is handled through the U.S. Embassy in Bangkok and the ustraveldocs.com platform. The process requires completing Form DS-160 online, paying the $185 MRV application fee, and attending an in-person interview. Approved B-1/B-2 visas for Thai nationals are typically issued for 10 years with multiple entries; the actual length of each stay is decided by a CBP officer at the port of entry (commonly up to 6 months / 180 days). Travelers should plan well ahead because interview appointment wait times in Bangkok can run from several weeks to a few months.