SummaryExercise and physical activity are thought to be among the most important lifestyle factors for the maintenance of health and prevention of premature disease and mortality. Yet sedentary lifestyles are common. Many people avoid exercise, and have done so across their lifespan. Exercise and physical activity are also considered important for positive psychological functioning; however, this has received limited research attention. This mini-review discusses the effects of exercise and physical activity on mental health and well-being in later life. It draws on international peer reviewed research, summarized in systematic reviews and/or meta-anlaysis, and presents the key findings. Systematic reviews and meta-analyses generally confirm the importance of exercise for mental well-being; however, there is a lack of good quality research. The review discusses some of the barriers to exercise, and identifies strategies that may facilitate uptake and adherence in later life. Limitations in the current evidence are discussed. Based on the current evidence, it is recommended that health practitioners should encourage exercise or physical activity of low to moderate intensity, and leisure time activity such as walking, especially at retirement. Future intervention research would benefit by focusing on people who have not self-selected into studies so as to understand the causal direction, and include theory driven approaches to behaviour change.