This research is motivated by the decline in customer loyalty at the Southeast Sulawesi Regional Development Bank due to suboptimal complaint handling and ineffective communication. In tight competition, especially during the Covid-19 pandemic, banks need to improve customer satisfaction to maintain their loyalty. This study aims to analyze the effect of relationship marketing on customer loyalty, the impact of customer satisfaction on loyalty, and the mediating role of customer satisfaction between relationship marketing and customer loyalty. The research method uses explanatory with the Structural Equation Modeling (SEM) approach on 100 credit customers. Data were collected through questionnaires to measure relationship marketing variables, customer satisfaction, and customer loyalty. The results show that relationship marketing has a significant but not large effect on customer loyalty (coefficient 0.256). Customer satisfaction has a strong effect on loyalty (coefficient 0.602) and is significant on relationship marketing (coefficient 0.548). Customer satisfaction also acts as an important mediator between relationship marketing and customer loyalty (indirect coefficient 0.330). The conclusion of this study is that the relationship marketing strategy implemented by the bank contributes to increasing customer loyalty through increasing their satisfaction. However, its direct influence still needs to be improved. Customer satisfaction is a key factor in increasing loyalty. Banks need to focus on increasing customer satisfaction through more effective relationship marketing strategies. Suggestions for the Southeast Sulawesi Regional Development Bank are to improve customer complaint handling and improve effective communication to build trust and loyalty. Banks must also continue to innovate in offering products and services according to customer preferences to maintain and increase long-term customer loyalty.