This book constitutes the proceedings of 22nd International Colloquium on Theoretical Aspects of Computing, ICTAC 2025, which took place in Marrakesh, Morocco, during November 24–28, 2025.The 21 full papers, 2 short papers and 1 tool paper presented in this book were carefully reviewed and selected from 64 submissions. The papers were categorized into the following topical sections: Invited Papers; Tutorial; Verification and Synthesis; Session Types; Logic and Theorem Provers; Probabilistic Systems; Automata; Cryptography and Choreography; Algorithms and Complexity; and Tool and Short Papers.