Purpose Internet of Things (IoT) is a key enabler of big data and it is critical toward a new age of firm's architecture and proper decision-making for the industry. IoT adoption by the hospitality and tourism (H&T) industries is still rare and with contrasting evidence. The purpose of this study is to highlight the concept of IoT, its benefits, its challenges and its applications in the hospitality industry. Design/methodology/approach This study presents an in-depth and critical review of the 78 articles published on IoT in hospitality, spanning more than seven years (from 2015 to March 2022). The eligible 78 articles were collected from the Web of Science database and H&T Social Sciences Citation Index-listed journals. Findings This systematic review exhibits that IoT in hospitality has advanced in the past seven years. IoT has brought many advantages and challenges in hospitality. However, hospitality IoT research is scarce, necessitating a profound and more thorough investigation of many significant matters. Practical implications This systematic review provides significant implications and recommendations for hospitality sectors, IoT developers and manufacturers, governments and policymakers. This review ends with an in-depth research agenda with several research questions and a framework to achieve theoretical and empirical advances in future IoT research. Originality/value To the best of the authors' knowledge, the current research is one of the first to systematically and critically review IoT with its concept, benefits, challenges and applications in a hospitality context. This major review provides a comprehensive idea of the focus of the past studies and what must be concentrated in future research.