This book constitutes the refereed proceedings of the 23rd International Symposium on Knowledge and Systems Sciences, KSS 2024, held in Hobart, Tasmania, Australia, during November 16-17, 2024. The 23 full papers presented in this book were carefully reviewed and selected from 50 submissions. They are organized in the following topical sections: Complex networks and modeling; Opinion dynamics; Knowledge technologies and systems engineering; Knowledge management.