In response to the COVID-19 pandemic and lockdown restrictions, telehealth physical activity intervention approaches are increasingly replacing face-to-face modes of delivery. At the University of Toronto, a face-to-face 6-week one-on-one and individualized physical activity program for post-secondary student mental health was adapted to online delivery. The effectiveness of the face-to-face program for student mental health has been demonstrated. Yet, the effectiveness of the online delivery approach is unknown. A pretest-posttest design was implemented to examine the effectiveness of the online program in promoting mental health and social connectedness among students identifying with poor mental health. Program participants (N = 26; M(SD)age = 25.32 (5.03) years; 92.3% female) completed self-report questionnaires to assess pre-post changes in mental health recovery, social connectedness, and depression and anxiety symptoms. Paired sample t-tests demonstrated a significant improvement in mental health recovery (M(SD)pre = 15.91 (4.99); M(SD)post = 18.58 (5.21)) and social connectedness (M(SD)pre = 3.56 (1.54); M(SD)post = 4.32 (1.41)) from pre to post intervention (ps <.05). A significant reduction in symptoms of depression (M(SD)pre = 11.54 (5.54); M(SD)post = 7.68 (5.54)) and anxiety (M(SD)pre = 9.92 (4.55); M(SD)post = 7.15 (4.87)) was also demonstrated (ps < .05). The results demonstrate the effectiveness of adapting a face-to-face physical activity intervention to online delivery in response to the COVID-19 pandemic, and offer insights into scalable programs for student mental health and well-being.