The coronavirus disease 2019 (COVID-19) presents varieties of questions concerning not only international law, but also the domestic laws of states affected by this global pandemic. One of legal issues amid COVID-19 pandemic is the state immunity principle. There have been many lawsuits against foreign state challenging the state immunity principle amid the COVID-19 pandemic. In Thailand, the Chiangmai Provincial Court (court) addressed in its judgment that it did not have jurisdiction to adjudicate the compensation for COVID-19 pandemic’s damages dispute between Thai restaurant owner and the United States (US). Notwithstanding surrounding controversies over COVID-19 pandemic, the court considered the motion denied. The main implication of the judgment is that Thailand accepted state immunity principle under customary international law. This research briefly explains the sovereign immunity doctrine relating to this case, summarizes the facts and analyses the potential ramifications of this judgement under international law.