Tourism workforce professionalization has increasingly become a critical determinant of service quality and destination competitiveness in the global tourism industry. This study examined the effect of professionalization of the tourism workforce on service quality delivery in Kenya's tourism sector. Grounded in Human Capital Theory and Institutional Theory, the study adopted a descriptive cross-sectional survey design targeting 17,654 registered tourism enterprises in Kenya, from which a sample of 396 enterprises was determined using the Yamane formula. Probability-proportional-to-size sampling was used to account for population heterogeneity and ensure that all classes of tourism enterprises were represented in the final sample. Primary data were collected using a structured Likert-scale questionnaire administered via Google Forms, yielding a response rate of 83.05%, while secondary data were obtained from peer-reviewed literature, books, and government policy documents. The findings revealed that respondents strongly acknowledged the importance of continuous professional development, formal qualifications, and employee professionalism in enhancing service quality and customer experience (M=4.01, SD=0.982; M=4.14, SD=1.184). Regression analysis established a strong and statistically significant relationship between workforce professionalization and service quality (R=0.683, p<0.001), indicating that workforce professionalization substantially explains variations in service quality within Kenya's tourism sector. The study concludes that enhancing service quality in the tourism sector requires shifting from a fragmented, project-based approach to workforce development to a more coordinated, institutionalized professionalization framework. Given that effective destination management relies on aligning tourism policy, regulatory systems, training institutions, and industry needs, workforce professionalization should be integrated as a strategic element of the destinations' governance and competitiveness agenda.