This book constitutes the refereed conference proceedings of the 4th Asian Symposium on Cellular Automata Technology, ASCAT 2025, held in Ranchi, India, during March 6-8, 2025. The 16 full papers included in this book were carefully reviewed and selected from 35 submissions. This symposium aims to explore the latest insights and innovations in multiple theoretical aspects of Cellular Automata Technology and their applications across various domains.