This book constitutes the proceedings of the 25th International Conference on Implementation and Application of Automata, CIAA 2021, held in July 2021. Due to Covid-19 pandemic the conference was held virtually. The 13 regular papers presented in this book were carefully reviewed and selected from 20 submissions. The topics of the papers cover various fields in the application, implementation, and theory of automata and related structures.

This book constitutes the proceedings of the 25th International Conference on Implementation and Application of Automata, CIAA 2021, held in July 2021. Due to Covid-19 pandemic the conference was held virtually. The 13 regular papers presented in this book were carefully reviewed and selected from 20 submissions. The topics of the papers cover various fields in the application, implementation, and theory of automata and related structures.