The objective was to compare the profile and outcomes of older adults admitted to a geriatric short-stay unit for COVID-19, to those of older adults admitted to the same unit for seasonal influenza infection. This was an observational study performed in a General Hospital in France. Patients ≥ 70 years admitted to a geriatric short-stay unit for COVID-19 between March 18 and November 15, 2020 were included. They were compared with patients of the same age group, admitted to the same geriatric short-stay unit for seasonal influenza infection over the periods January to March 2019 and January to March 2020. Data collection included demographic information, medical history, clinical signs and symptoms, outcomes, and hospital discharge patterns. Descriptive and intergroup comparison analyses were performed. In total, 153 patients were included in the study, 82 in the seasonal influenza group, and 71 in the COVID-19 group. The average age was 87.6 ± 4.8 and 87.6 ± 6.5 years in the COVID-19 and seasonal influenza groups, respectively. There was no difference between groups regarding the Charlson comorbidity index (3.4 ± 3.0 versus 3.4 ± 2.8). The seasonal influenza group more often had fever, cough, sputum, and renal failure, whereas the COVID-19 group more often experienced diarrhea, and death. The COVID-19 group was frequently living in collective housing. The profile at admission of older adults hospitalized for COVID-19 or seasonal influenza infection was similar. Although fever and respiratory signs were less common in the COVID-19 group, these patients experienced more complications (such as renal failure or oxygen therapy requirement) and higher mortality.