Several diseases, including both noninfectious diseases and bacterial and viral diseases, are associated with the ABO and RH blood group systems. Previous studies have shown a link between blood type and the probability of coronavirus disease 2019 (COVID-19) infection. In this study, we aimed to explore the correlation between deaths caused by COVID-19 and ABO and RhD blood types in Saudi Arabia. In this cross-sectional observational study, data from COVID-19 patients were collected from 2 major hospitals treating COVID-19 in Riyadh City, Saudi Arabia, between March 2020 and November 2021. The association between ABO and RhD blood types and COVID-19 outcomes was investigated. A total of 2302 real-time polymerase chain reaction-confirmed COVID-19 patients were enrolled in this study; a chi-square test was used to determine the statistical significance of the data. Of the 2302 enrolled patients, 1008 (43.8%) had blood type O, 677 (29.41%) had blood type A, 502 (21.8%) had blood type B, and 115 (5%) had blood type AB. Of the patients, 2143 (93.1%) were RhD-positive. The O-positive blood type had the highest mortality rate among COVID-19-infected patients, whereas the AB-negative type had the lowest. However, statistical analysis revealed no significant correlation between blood type (ABO or RhD) and COVID-19-based susceptibility or mortality. In conclusion, we found no association between ABO and RhD blood types and either susceptibility to or mortality due to COVID-19 in Saudi Arabia.