This book constitutes the refereed proceedings of the 17th International Conference on Scalable Uncertainty Management, SUM 2026, held in Athens, Greece, during October 21–23, 2026. The 23 full papers and 6 short papers included in the proceedings were carefully reviewed and selected from 38 submissions, also includes two invited extended abstracts. They focus on Artificial Intelligence, Uncertainty Reasoning, Logic, Databases, Machine Learning, Information Retrieval, Data Mining, Semantic Web, Risk Analysis, Conditionals, Inconsistency, Elicitation, Incomplete Knowledge, Argumentation.
