This study aimed to examine the impact of digital transformation on the sustainability of banking service quality in public commercial banks in Zawia City. Digital transformation was conceptualized through four dimensions: digital infrastructure, electronic banking services, banking automation, and financial technology (FinTech). The sustainability of banking service quality was measured through five dimensions: reliability, responsiveness, banking security, customer satisfaction, and service continuity. The study adopted a descriptive-analytical approach and employed a structured questionnaire as the primary data collection instrument. The study sample consisted of 150 employees from public commercial banks in Zawia City. Data were analyzed using IBM SPSS Statistics through a range of statistical techniques, including descriptive statistics, Cronbach’s Alpha reliability analysis, Pearson correlation analysis, simple linear regression analysis, and tests of statistical differences. The findings revealed a high level of digital transformation implementation within public commercial banks in Zawia City, with an overall mean score of 3.79. Similarly, the sustainability of banking service quality recorded a high level, with an overall mean score of 3.81. The results further indicated a strong positive and statistically significant relationship between digital transformation and the sustainability of banking service quality (r = 0.742, p < 0.01). Moreover, regression analysis demonstrated that digital transformation accounted for 55.1% of the variance in the sustainability of banking service quality (R² = 0.551), highlighting its substantial explanatory power. The study concludes that digital transformation constitutes a critical strategic driver for enhancing and sustaining banking service quality in public commercial banks in Zawia City. Accordingly, it recommends strengthening digital infrastructure, expanding electronic banking services, accelerating banking automation initiatives, and investing in the development of human capital capabilities to improve operational efficiency, enhance customer satisfaction, and support the long-term sustainability of banking services............... Keywords:.............. Digital Transformation; Sustainability of Banking Service Quality; Public Commercial Banks in Zawia City.