(1) Background: Nowadays, it is essential to implement new non-pharmacological strategies, such as rhythmic physical activity, to improve mental health and quality of life in both individuals experiencing normal brain aging and those with cognitive impairment. Therefore, the objective of this study is to identify the effects of rhythmic physical activity interventions on mental health and quality of life in older adults, with or without mild cognitive impairment; (2) Methods: We conducted a systematic review with a meta-analysis, searching the Pubmed, Scopus, Web of Science, and Cochrane Plus databases using specific keywords. We selected studies that included rhythmic physical activity as the primary intervention for patients aged 65 and above, with or without cognitive impairment. We assessed the methodological quality of the articles using the PEDro scale; (3) Results: Out of 961 identified studies, we included 11 in this review, all of which employed rhythmic physical activity as an intervention. The selected studies consistently measured depression, anxiety, and quality of life; (4) Conclusions: This review demonstrates that rhythmic physical activity can effectively improve depression, anxiety, and quality of life in older adults, whether or not they have mild cognitive impairment. However, it is worth noting that while we have identified beneficial outcomes, the evidence supporting the use of rhythmic physical activity in enhancing depression, anxiety, and quality of life in older adults with or without mild cognitive impairment remains somewhat limited.