Digital marketing has become essential in the tourist and events industry, increasing visibility and attractiveness. This research aims to examine the effect of digital marketing on event image and sustainable destination image. Furthermore, it explores the reciprocal impact of the sustainable destination image on the event image. A sample of 400 residents who attended and participated in the Santa Tecla festival in Tarragona, Spain, provided data via in-person and online questionnaires. Multiple regression analysis was conducted to evaluate the hypotheses. The findings show that digital marketing significantly impacts event image but has little effect on sustainable destination image. Moreover, a significant reciprocal effect exists between a sustainable destination image and an event image. These findings highlight the importance of digital marketing and the promotion of event sustainability in shaping public opinion and attitudes towards events and destinations. This research has important implications for theory and practice in tourist marketing and event management. It offers unique perspectives on enhancing digital marketing strategies to promote sustainable events and destinations.