Background and Purpose: Mechanical changes at ankle and subtalar joint complex contribute to altered foot posture in individuals with Knee OA. However, there is a dearth of literature on the role of ankle joint position sense and foot posture on severity of osteoarthritis and functional disability. The primary aim of this study was to know the role of ankle joint position sense and foot posture on severity of knee osteoarthritis and functional disability in patients with Osteoarthritis. Methodology: The study was performed on 120 subjects aged between 40-70 years of age. The study sample consisted of individuals diagnosed with osteoarthritis of knee joint with Knee pain (VAS ≤ 7/10) for at least 1-month duration. Knee radiographs were graded by an orthopedic surgeon following which subjects were evaluated for FPI 6, ankle JPS using bubble inclinometer and WOMAC scale. Results: Results of pearson’s and spearman’s test showed a positive correlation of ankle JPS and FPI with functional disability respectively (r=0.5222, r=0.9644 respectively with p value <0.05) but no significant correlation was found with severity of Knee OA. Also observed was an extremely significant positive correlation between Foot Posture Index (FPI) and ankle Joint Position Sense (JPS) (r=0.6354, p value<0.05). Conclusion: The present study concludes that altered foot posture and ankle JPS is a contributory factor to functional disability but does not show a significant effect on severity of disease in patients with knee osteoarthritis.