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.