The tourism industry thrives on a multifaceted nexus among service quality, tourist satisfaction, delight, and sustainability. In particular, the tourism industry in Saudi Arabia brings prosperity and economic support by organizing cultural festivals and events in Riyadh. Therefore, this study investigates the direct effects of service quality on tourist satisfaction, delight, and sustainability. Additionally, this study also examines the mediating role of tourist satisfaction and delight on the one hand and the moderating role of trip experience and value. Employing a quantitative research approach, this study used a structured survey questionnaire to collect data from 430 international tourists who visited festivals and events in Riyadh, Saudi Arabia. Using Smart PLS, SEM was used to test the hypotheses. The findings revealed a strong positive effect of service quality on tourist satisfaction and delight and, in turn, on tourism sustainability. Tourist satisfaction and delight mediate the relationship between service quality and tourism sustainability. This study further established significant moderating effects between trip value and service quality on tourist delight. Accordingly, the tourism industry should prioritize high service quality as it significantly influences tourist perceptions and sustainable outcomes. Additionally, trip experiences and higher service quality lead to higher tourist satisfaction and delight. Furthermore, while not directly determining satisfaction, perceived value plays a pivotal role in strengthening tourist delight when combined with top-tier service quality.