Nyaru Menteng Ecotourism is an education-based conservation destination in Palangka Raya that holds considerable potential, yet still faces limitations in service quality and facilities that may affect visitor satisfaction and loyalty. This study aims to examine the effect of Service Quality on Tourist Loyalty, both directly and indirectly through Tourist Satisfaction as a mediating variable, at Nyaru Menteng Ecotourism. This study employed a descriptive design with a quantitative approach, involving 55 respondents selected through purposive sampling, with data collected using a 1-5 Likert-scale questionnaire and analyzed using the Partial Least Square-Structural Equation Modeling (PLS-SEM) method through SmartPLS 4.1. The results show that Service Quality has a positive and significant effect on Tourist Satisfaction, Service Quality has a positive and significant effect on Tourist Loyalty, Tourist Satisfaction has a positive and significant effect on Tourist Loyalty, and Service Quality has a positive and significant effect on Tourist Loyalty through Tourist Satisfaction as a partial mediator. These findings indicate that improving service quality, particularly in terms of tangibility, empathy, and assurance, can enhance satisfaction while simultaneously driving tourist loyalty, both directly and through satisfaction first. The practical implication of this study is the importance for the management of Nyaru Menteng Ecotourism to continuously improve facility quality, cleanliness, and safety assurance in order to sustain visitor satisfaction and loyalty over the long term