Background Adult-onset Still’s disease (AOSD) is a multi-system, auto-inflammatory disease characterized by fever, arthralgia, typical rash, leukocytosis, sore throat, and liver dysfunction, among other symptoms. Retrospective studies about the frequencies of AOSD have shown that this disease is very rare. However, there has been an increased scientific interest in the last 2 years, as numerous case studies on AOSD have been published. These case studies describe the occurrence of AOSD after SARS-CoV-2 infection and/or COVID-19 vaccination. Methods We analyzed the incidence of AOSD to examine a potential association between AOSD and SARS-CoV-2 infection and/or COVID-19 vaccination. The TriNetX dataset consists of 90 million patients. We found 8474 AOSD cases, which we analyzed regarding SARS-CoV-2 infection and/or vaccination status. We also analyzed the cohorts considering demographic data, lab values, co-diagnoses and treatment pathways. Results We divided the AOSD cases into four cohorts: primary cohort (AOSD), Cov cohort (AOSD + SARS-CoV-2 infection), Vac cohort (AOSD + COVID-19 vaccination) and Vac + Cov cohort (AOSD + COVID-19 vaccination + SARS-CoV-2 infection). For the primary cohort, we found an annual incidence of 0.35 per 100.000. We found an association between AOSD and SARS-CoV-2 infection and/or COVID-19 vaccination. According to the numerical analysis, the incidence of AOSD doubled for the Cov cohort and Vac cohort. Moreover, the incidence of AOSD was 4.82 times higher for Vac + Cov cohort. The lab values for inflammatory markers were increased. Co-diagnoses such as rash, sore throat, and fever appeared in all AOSD cohorts, with the highest occurrences in the AOSD + COVID-19 vaccination + SARS-CoV-2 infection cohort. We identified several lines of treatments, mainly in association with adrenal corticosteroids. Conclusions This research supports the assumption of an association between AOSD and SARS-CoV-2 infection and/or COVID-19 vaccination. However, AOSD remains a rare disease and the usage of vaccines to fight the COVID-19 pandemic should not be questioned because of the increased incidence of AOSD.