Researchers conducted this cross-sectional study to explore the connection between sedentary behavior and chronic knee pain in a study population representative of the general Korean population aged > 50 years while also considering the physical activity or BMI. In this investigation, data from Korea’s 6th National Health and Nutrition Examination Survey (KNHANES VI), 2013–2015 were utilized. In total, 22,948 candidates completed the KNHANES VI-1 (2013), VI-2 (2014), and VI-3 (2015) examinations and health surveys. Findings suggested an association of longer duration of sedentary behaviors with chronic knee pain. Findings suggest that reduction of overall sedentary behavior to < 10 h daily should be encouraged. It is recommended to have high levels of physical activity, especially for women > 50 years and those with obesity.