This volume constitutes the proceedings of the 16th International Conference on Intelligent Tutoring Systems, ITS 2020, held in Athens, Greece, in June 2020. The 23 full papers and 31 short papers presented in this volume were carefully reviewed and selected from 85 submissions. They reflect a variety of new techniques, including multimodal affective computing, explainable AI, mixed-compensation multidimensional item response, ensemble deep learning, cohesion network analysis, spiral of silence, conversational agent, semantic web, computer-supported collaborative learning, and social network analysis.