This volume constitutes the proceedings of the 15th International Conference on Sustainable Digital Communities, iConference 2020, held in Boras, Sweden, in March 2020.The 27 full papers and the 48 short papers presented in this volume were carefully reviewed and selected from 178 submissions. They cover topics such as: sustainable communities; social media; information behavior; information literacy; user experience; inclusion; education; public libraries; archives and records; future of work; open data; scientometrics; AI and machine learning; methodological innovation.