Background: The ongoing COVID-19 has had a huge worldwide influence. Vaccinations are a crucial component of illness prevention. Thailand’s vaccination program for children above the age of five is in its initial stages. Many Thai parents are still unwilling to vaccinate their children with the COVID-19 vaccine. The purpose of this study was to analyze the rate of parental hesitancy and influential variables among Thai parents and guardians living in Thailand. Methods: This was a cross-sectional survey in Thailand during October and November of 2021. Through online social media networks, an online survey (REDcap) was distributed. Thai parents and guardians with at least one child under the age of 18 were invited to participate. Results: A total of 1064 responses for analysis. One thousand and sixty-four were available for analysis with 74.4% of those who participated being female. The results found that the parental COVID-19 vaccination hesitancy rate was higher among parents with children under the age of 12 than among parents with children over the age of 12. (56.9% vs 17.1%, p-value < 0.001). Parents were more concerned about vaccination side effects (82.5%), safety (60.0%), and vaccine efficacy (37.2%). Low vaccine reluctance among parent with children age less than 12 years old was associated with higher education (aOR = 0.35, 95 %CI = 0.13–0.93, p-value = 0.036) and a favorable attitude regarding covid-19 immunizations (aOR 0.16, 95% CI 0.04–0.67, p-value 0.012) Conclusion: The majority of Thai parents with children under the age of 12 were hesitant to vaccinate against COVID-19. To minimize Thai parent vaccination hesitancy and increase vaccine uptake among children, the government and health care providers should target this population with evidence-based information, promote positive attitudes toward COVID-19 vaccinations, and encourage educated parents to vaccinate their children at first.