This book constitutes the proceedings of the 11th International Conference on Modelling and Simulation for Autonomous Systems, MESAS 2024, which took place in Chania, Crete, Greece, during October 1–3, 2024.The 16 full papers included in this book were carefully reviewed and selected from 23 submissions. They were organized in topical sections as follows: M&S of Intelligent Systems - R&D and Application; Future Challenges of Advanced M&S Technology; and AxS/AI in Context of Future Warfare and Security Environment.