This volume constitutes the proceedings of 25th International Conference on Embedded Computer Systems: Architectures, Modeling, and Simulation, SAMOS 2025, in Samos, Greece, during June 28–July 3, 2025.The 18 full papers, 12 short papers and 2 special session papers were included in this book were carefully reviewed and selected from 63 submissions. This conference orgamised in the follwing topcial sections as follows as Simulation, Emulation, and Design Space Exploration; Security; Tools and Frameworks; Reliable and Real-Time Systems; High Performance and Time Predictable Architectures; Application and Acceleration.