This book constitutes the proceedings of the 13th International Conference on Big Data Analytics in Astronomy, Science, and Engineering, BDA 2025, which took place in Aizu, Japan during November 26-28, 2025.The 23 full papers in this book were carefully reviewed and selected from 145 submissions. They were organized in topical sections as follows: Big Data: Management and Visualization ; Data Science: Architecture and Systems; Data Science and Applications; Information Security and Cloud Computing.