INTRODUCTION: This study aims to examine the relationship between COVID-19 vaccination and subjective well-being (SWB), as well as well-being inequality. It employs a conceptual framework that incorporates demographic characteristics, socioeconomic factors, health, and social support. METHODS: Using data from the Gallup World Poll (2021-2022), which includes 131,910 respondents across 96 countries, we analyze the association between vaccination status and SWB. The Cantril ladder technique is employed to measure SWB, while regression analyses are conducted to estimate the conditional mean and variance of well-being, allowing for an assessment of well-being inequality. RESULTS: Our findings indicate that vaccinated individuals report significantly higher levels of current SWB (p <
.01) and lower well-being inequality (p <
.01) than unvaccinated people. Specifically, vaccination is associated with a 0.04 standard deviation increase in SWB and a 0.06 standard deviation decrease in interpersonal well-being inequality. Moreover, those vaccinated exhibit greater optimism regarding their future well-being. CONCLUSION: The results underscore the importance of COVID-19 vaccination in enhancing both current and expected future well-being while reducing well-being inequality. These findings suggest that public health policies should prioritize vaccine uptake and address underlying socioeconomic factors to promote overall mental health and well-being in the population.