Introduction Stigma has inhibited public health practitioners’ influence during the COVID-19 pandemic. We explore the experienced and anticipated stigma of people affiliated with a large university in the United States, using the Health Stigma and Discrimination Framework. Methods We conducted a qualitative secondary substudy of 20 people who tested SARS-CoV-2 positive and 10 who tested negative in the summer of 2020, selected from a study of 3,324 university students and employees. Findings No participants reported anticipated stigmatization prior to testing positive. However, eight of 20 participants recounted stigma marking (being marked by COVID-19 diagnosis or membership in a “high-risk” group) or manifestations of stigma after testing positive, including feelings of guilt or shame, and concerns about being judged as selfish or irresponsible. Three described being denied services or social interactions as a result of having had COVID-19, long after their infectiousness ended. Participants noted that clear public health messaging must be paired with detailed scientific information, rather than leaving people to resort to non-experts to understand the science. Discussion Public health messaging designed to mitigate spread of SARS-CoV-2 and protect the community may perpetuate stigma and exacerbate inequities. As a result, people may avoid testing or treatment, mistrust public health messaging, or even use risk-increasing behavior as coping mechanisms. Implications for Practice Intentional use of language that promotes equity and deters discrimination must be high priority for any COVID-19-related public health messaging. Partnership with community leaders to co-create programs and disseminate messaging is a critical strategy for reducing stigma, especially for historically mistreated groups.