This book constitutes the proceedings of the 22nd International Conference on Descriptional Complexity of Format Systems, DCFS 2020, which was supposed to take place in Vienna, Austria, in August 2020, but the conference was canceled due to the COVID-19 crisis.

The 19 full papers presented in this volume were carefully reviewed and selected from 31 submissions. They deal with all aspects of descriptional complexity and costs of description of objects in various computational models, such as Turing machines, pushdown automata, finite automata, grammars, and others.