This research examines the relationship between sources of knowledge and innovation in companies in the accommodation, restaurant, and food service sector. The research is quantitative and uses data from the Colombian Survey of Technological Development and Innovation in Services. The results indicate that internal sources and customers are positively related to service innovation, while competitors are inversely related to service innovation. In addition, internal sources and competitors are positively related to process innovation, while suppliers are inversely related to process innovation. Regarding the control variables, company size is positively related to service innovation, and membership in a business group is positively related to process innovation. The research has theoretical implications as it shows us how internal sources and customers are the sources where knowledge for service innovation comes from, while internal sources and competitors are the sources where knowledge for process innovation comes from, which contributes to the literature because there is little literature regarding the sources of knowledge that relate to innovation in companies in the accommodation, restaurant, and food service sector, where evidence is scarce. The research has practical implications because administrators and managers of companies in the accommodation, restaurant, and food service sector can define strategies to use these sources of knowledge that relate to the innovation of services and processes, in order to increase the innovative potential of their company in this sector.