The treatment of Type 2 Diabetes Mellitus (DM2) comprises physical activity (PA), diet, and medication. PA provides important benefits for people with diabetes. However, the majority of patients with DM2 do not attain the recommended levels of PA. Despite the evidence of the benefits to health of engaging in PA, the recommendations have not been fully translated into clinical improvements. Using a scoping review, this study aimed to identify the factors that influence levels of physical activity in adults with DM2. Eighteen studies published from 2009–2020 were identified by a search of relevant systematic databases between March 2019 and December 2020. The scoping review was carried out in accordance with the model defined by Arksey and O’Malley. The synthesis revelated sociodemographic characteristics, and six components—personal, motivation, social, mental, clinical, and self-efficacy—were identified as factors. Those that were most frequently identified were motivation and social support. In conclusion, these results should be considered to implement strategies to encourage people with DM2 to engage in physical exercise and thus improve the management of their condition.