This book constitutes the refereed proceedings of the 36th IFIP WG 6.1 International Conference on Testing Software and Systems, ICTSS 2024, held in London, UK, during October 30-November 1, 2024. The 17 full papers and 5 short papers included in this book were carefully reviewed and selected from 40 submissions. They were organized in topical sections as follows: Best Paper Award; Industry and Challenge Tracks; Mutation Testing and Code Generation; Advancing Code Vulnerability Detection; Short Papers; Tutorial; Journal First; Health Track; Innovations in Software Testing and AI Compliance; Improving Software Testing Reliability and Advancements in Testing Methodologies.