This volume contains the papers presented at EC-TEL 2020: 15th European Conference on Technology-Enhanced Learning held on September 14-18, 2020. To encourage presentations that address real world problems or practical use cases, ECTEL invited both practitioners and researchers to submit impact papers. The impact track aimed at sharing thoughts and ndings that stem from TEL projects and were transferred into practice and/or at scale including formal or informal pilot studies or iterative designbased research. These papers include the application, implementation, commercial aspects or practical challenges in innovating education through technology, in particular in the context of the EC-TEL conference theme "Addressing global challenges and quality education". Impact papers illuminate from a practical point of view how emerging and future learning technologies can be better understood by learners and educators and how they can be used in a meaningful way to enhance human-machine interrelationships and to contribute to e cient and e ective education. Thus, impact papers are based on a practical use of technology for learning to improve, change or enhance learning practice in formal as well as informal learning environments including an expected pedagogical value. The objective is to promote a discussion between research and practice, such that on the one hand, practical experiences and challenges are made known to researchers, and ongoing research is made known to practitioners. Impact papers were submitted and reviewed through the EC-TEL rigorous submission process, which means that each paper was reviewed by at least two reviewers and from the Impact track chairs. The 8 papers included in the Impact track will be published as companion to the EC-TEL proceedings in ceur-ws.org and linked on the EA-TEL.eu website and presented during the main conference. We thank all of the authors who prepared submissions, our programme committee, reviewers and sponsors for their hard work during these challenging times.