We investigated the associations between physical activity, physical inactivity, and ovarian cancer risk and identified the most effective physical activity intensity and amount to reduce ovarian cancer risk. Thirty-four studies were selected for the present meta-analysis. Physical activity helps decrease ovarian cancer risk. Moderate intensity and low amount of physical activity showed the greatest reduction of ovarian cancer risk and prolonged sitting time had the worst ovarian cancer risk. At least 2 h of moderate physical activity per week and <3 h of sitting time per day provided a preventive effect to ovarian cancer.