This book constitutes the refereed proceedings of the workshops held at the 45th International Conference on Conceptual Modeling, ER 2026, which took place in St. John's, NL, Canada, October 5–8, 2026.

The 5 full papers included in this book were carefully reviewed and selected from 9 submissions.The workshops focused on topics of interest to the conceptual modeling community and their applications in different domains.

Two workshops were organized at ER 2026. These were:

• 7th International Workshop on Conceptual Modeling for Life Sciences (CMLS)
• 4th International Workshop on Modeling in the Age of Large Language Models (LLM4Modeling)