Purpose: This study aimed to estimate the prevalence and severity level of stigma experienced by patients who recovered from COVID-19 in the post-vaccination period and to explore associated factors. Methods: This study consisted of two phases. The first phase involved the translation and validation of the COVID-19-related stigma questionnaire (15 items). The second phase was a questionnaire-based cross-sectional survey conducted between January and February 2022. Questionnaires regarding stigma, negative emotions (Depression Anxiety Stress Scale-21), and personal and admission information were given to patients who recovered from COVID-19 in Thailand (N = 354). Results: The prevalence of stigma among patients who recovered from COVID-19 was 50.8%. Slight, moderate, and high stigma levels were reported by 40.7%, 9.3%, and 0.8% of the total participants, respectively. Our study found that admission duration and recovery duration were inversely related to stigma. Whereas depression, anxiety and stress were directly correlated with stigma. Other associated factors included age, income and education level. Conclusion: Social stigma related to COVID-19 existed even after vaccination and still took a toll on mental health. Stigma might decrease through time in patients who recovered from COVID-19, but not completely disappear. Our findings suggested providing appropriate assessment and help to patients who recovered from COVID-19, especially during the initial stage of their return to the community.