Background: Physical activity (PA) may play a significant role in managing post-Coronavirus Disease (COVID)-19 syndrome, a significant public health concern among older adults. This study aimed to systematically review the evidence on post-COVID-19 symptoms, signs, risk factors, and the effects of PA programs in managing post-COVID-19 syndrome among older adults. Method: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendation. The systematic search was conducted in August 2022 using Scopus and MEDLINE (via PubMed) databases. Results: There were 51 documents screened, among which 10 (7 observational and 3 experimental studies) met the selection criteria. The reported post-COVID-19 symptoms and signs associated with physical health included dyspnea, fatigue, diarrhea, and sarcopenia, abnormal lung function, cardiac pathology, immunological changes, reduced physical performance, respectively, while those associated with mental health included depression, poor concentration and memory, and anxiety. Patients with higher body mass indexes were more likely to experience more symptoms. Older patients had greater difficulties in performing daily activities and mobility. A multidisciplinary-based PA program is suggested to be feasible and effective in improving fatigue, ability to walk, balance, and cognitive function. For patients with sarcopenia, a low-intensity aerobic training exercise appears to improve muscle strength, kinesiophobia, and quality of life. Conclusion: Various post-COVID-19 symptoms have been reported along with their risk factors, and PA programs are potentially used for managing these symptoms. More research, however, is recommended to explore the PA program for specific post-COVID-19 symptoms.