Background: Bell's palsy is characterized by the sudden onset of facial paralysis due to facial nerve inflammation. Accurate assessment tools, such as the House-Brackmann Facial Grading System (HBFGS), are essential for evaluating the severity of facial nerve dysfunction. This study aimed to translate and validate the Urdu version of HBFGS for Urdu-speaking patients, enhancing its reliability and applicability. Objective: To translate the HBFGS into Urdu and evaluate its reliability and validity in assessing facial nerve function among Urdu-speaking patients with Bell's palsy. Methods: A cross-sectional study was conducted with 245 participants diagnosed with Bell's palsy. The UHBFGS was developed through forward-backward translation and cultural adaptation. Participants' facial motor function was assessed using the UHBFGS by trained physiotherapists. Reliability was evaluated using Cronbach’s alpha and intraclass correlation coefficient (ICC), while SPSS version 25 was used for data analysis. Results: The UHBFGS demonstrated high internal consistency (Cronbach’s alpha = 0.951) and excellent test-retest reliability (Pearson’s r = 0.907). Inter-rater reliability was confirmed with an ICC of 0.888. Grade 3 severity was most common, affecting 43% of participants. Conclusion: The Urdu version of the HBFGS is a reliable and valid tool for assessing facial nerve function in Urdu-speaking patients, facilitating improved clinical evaluation and patient management.