Abstarct: The purpose of this study was to examine the effect of experiential marketing on customer engagement in fitness centers, with word-of-mouth advertising as a mediating variable. The present study employed a descxriptive–correlational design and was cross-sectional in terms of time. The statistical population included customers of licensed fitness centers in Iraq, and ultimately, 288 participants were selected as the research sample using a multi-stage sampling method. Data were collected using the 19-item Experiential Marketing Questionnaire by Hii and Young (2013), the 3-item Word-of-Mouth Advertising Questionnaire by Acosto-Norris (2018), and the 9-item Customer Engagement Questionnaire by Doyle et al. (2013). The research instruments were validated by experts and specialists in sports management, and the reliability of the instruments was confirmed using Cronbach's alpha test. For data analysis, descxriptive statistics, correlation coefficients, and Structural Equation Modeling (SEM) were employed. The results indicated that experiential marketing has a direct and significant impact on customer engagement, and word-of-mouth advertising plays an important mediating role in strengthening this relationship. The findings suggest that fitness centers can enhance customer engagement and informal advertising by designing multidimensional and positive experiences for their customers. This study provides practical guidance for fitness center managers and sports policymakers to improve organizational performance and customer satisfaction through experiential marketing and encouragement of word-of-mouth advertising.