This book constitutes the referred proceedings of the 6th International Conference on Machine Learning for Cyber Security, ML4CS 2024, held in Hangzhou, China, during December 27-29, 2024. The 30 full papers presented in this book were carefully reviewed and selected from 111 submissions. ML4CS is a well-recognized annual international forum for AI-driven security researchers to exchange ideas and present their works. The conference focus on topics such as blockchain, network security, system security, software security, threat intelligence, cybersecurity situational awareness and much many more. .