This study examines the impact of service quality on customer satisfaction and loyalty in RELIANCE JIO. It employs the five service quality dimensions—tangibles, reliability, assurance, empathy, and responsiveness—proposed by Parasuraman, Berry, and Zeithaml (1991). Data were collected through a structured questionnaire from RELIANCE JIO customers in Surkhet Valley. Using multiple regression analysis, the findings reveal a significant positive relationship between all service quality dimensions and both customer satisfaction and loyalty. Among these, "Reliability" emerges as the most influential factor in customer satisfaction, while "Empathy" has the strongest impact on customer loyalty. Additionally, customer satisfaction is identified as a key driver of customer loyalty. The study concludes that service quality is a crucial determinant of both satisfaction and loyalty. Based on these findings, RELIANCE JIO ’s management can develop effective customer service strategies to enhance corporate value and foster long-term customer relationships.