ABSTRACTThis study investigates regional similarities and differences in the tourism research knowledge domain, based on two decades of publications. The authors analysed co-citations in the reference lists of full-length articles published in Annals of Tourism Research (1998–2017) in relation to four regions: North America, Europe, Asia, and the Pacific and Oceania. The findings reveal a degree of regional fragmentation in the tourism research knowledge domain. Several wide discourses characterize the scope of tourism knowledge: authenticity and the tourist experience, backpacker tourism, consumer behaviour, destination life cycle, tourism impacts and resident attitudes, paradigms, performance approach, and volunteer tourism. The authors document the contribution of each region to these discourses. Implications of regional distinctions are discussed along with future research opportunities.