In addition to the classic motor symptoms, Parkinson’s disease (PD) is associated with a variety of non-motor symptoms that significantly reduce quality of life, even in the early stages of the disease. There is an urgent need to develop evidence-based treatments for these symptoms, which include mood disturbances, cognitive dysfunction, and sleep disruption. We focus here on exercise interventions, which have been used to improve mood, cognition, and sleep in healthy older adults and clinical populations, but to date have primarily targeted motor symptoms in PD. We synthesize the existing literature on the benefits of aerobic exercise and strength training on mood, sleep, and cognition as demonstrated in healthy older adults and adults with PD, and suggest that these types of exercise offer a feasible and promising adjunct treatment for mood, cognition, and sleep difficulties in PD. Across stages of the disease, exercise interventions represent a treatment strategy with the unique ability to improve a range of non-motor symptoms while also alleviating the classic motor symptoms of the disease. Future research in PD should include non-motor outcomes in exercise trials with the goal of developing evidence-based exercise interventions as a safe, broad-spectrum treatment approach to improve mood, cognition, and sleep for individuals with PD.