In light of current industry imperatives and growing scholarly attention, this study was conducted to provide a thoroughly updated bibliometric overview of how service innovation research has evolved. A total of 133 papers across 42 hospitality and tourism journals over 18 years (2003–2020) were extracted and analyzed. We first examined the publication outlets and trajectories of service innovation. Next, we applied several state-of-the-art bibliometric techniques, including co-citation and keyword co-occurrence analysis. Based on the results of co-occurrence analysis, we proposed a flowchart of the service innovation process combining organizational and customer perspectives while considering the service design, process, and outcome phases. We then summarized the major findings and limitations of service innovation studies in hospitality and tourism. A series of critical future research directions were presented accordingly.