Background Serosurveys are important to ascertain burden of infection. Prior SARS-CoV-2 serosurveys in New York City (NYC) have used nonrandom samples. During June–October 2020, the NYC Health Department conducted a population-based survey to estimate SARS-CoV-2 antibody prevalence in NYC adults. Methods Participants were recruited from the NYC 2020 Community Health Survey. We estimated citywide and stratified antibody prevalence using a hybrid design: serum tested at the NYC Health Department using the DiaSorin LIAISON ® SARS-CoV-2 S1/S2 IgG assay and self-reported antibody test results were used together. Prevalence was estimated using univariate frequencies and 95% confidence intervals (CI), accounting for complex survey design. Two-sided P-values ≤0.05 were statistically significant. Results There were 1074 respondents overall; 497 provided blood and 577 provided only a self-reported antibody test result. Weighted prevalence was 24.3% overall (95% CI: 20.7–28.3). Latino (30.7%, 95% CI: 24.1–38.2, p<0.01) and Black (30.7%, 95% CI: 21.9–41.2, p=0.02) respondents had a higher weighted prevalence compared with White respondents (17.4%, 95% CI: 12.5–23.7). Conclusions By October 2020, nearly 1 in 3 Black and 1 in 3 Latino NYC adults had SARS-CoV-2 antibodies, highlighting unequal impacts of the COVID-19 pandemic on Black and Latino adults in NYC.