This book constitutes the refereed proceedings of the 23rd EAI International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services, MobiQuitous 2026, held in Beppu, Japan, during November 16–18, 2026.

The 40 full papers and 14 poster and demo papers presented in this volume were carefully reviewed and selected from 138 submissions. They are organized into the following topical sections: Edge Intelligence; Human Sensing; Security and Privacy; Mobility and Networks; AR and Interaction; Industry Track; 6th International Workshop on Mobile Ubiquitous Systems, Infrastructures, Communications and AppLications (MUSICAL’26 Fall); Posters and Demos.