Since social media has become an essential tool in the contemporary hotel industry, companies are now building social media communities to engage customers online (Leung & Bai, 2013) and to maintain satisfaction, trust, commitment, loyalty, and brand relationship quality (Harrigan, Evers, Miles, & Daly, 2017). Despite global hotel companies’ increasing adoption of social media platforms to promote customer engagement, research in this area is still sparse (Harrigan et al., 2017; So, King, & Sparks, 2014). To fill this gap, the authors developed a theoretical model incorporating two antecedents (hotel brand experience and customer involvement to social media) and a consequence (brand relationship quality) of customer engagement (CE) in the context of hotel brand communities embedded in social media. Additionally, the authors included hotel brand reputation (HBR) in the model as another predictor of brand relationship quality (BRQ). This study obtained data from a panel survey consisting of the responses of hotel customers who had stayed at one of ten famous hotel brands in the U.S. within the past 12 months and were simultaneously followers of the hotel brand’s page on Facebook. The findings reveal that both antecedents (ISM and HBX) positively and significantly influence CE and that hotel brand experience (HBX) has a stronger impact on CE than ISM. The findings also demonstrate that CE has the strongest, positive effect on BRQ, followed by HBX and HBR. Furthermore, the findings indicate that the relationship between HBX and BRQ is partially and significantly mediated by CE. This research provides theoretical and practical contributions to the field. First, unlike previous studies, the current study utilized the concept of CE with hotel brand communities embedded in social media as a mediator between HBX and BRQ and found partial and significant mediation effects. Second, the study identified two new and crucial antecedents of CE with brand communities embedded in social media—customer brand experience and customer social media involvement. Third, this study found brand relationship quality as one of the primary outcomes of customer engagement with hotel brand communities in social media. Lastly, the findings confirm that social media-based brand communities (i.e., Facebook) are one tool companies can use to build long-lasting customer-brand relationships.