This book constitutes the proceedings of the 18th International Conference on Tests and Proofs, TAP 2024. TAP 2024 took place in Milan, Italy, on September 9 and 10, 2024 as part of the Formal Methods symposium (FM 2024), which included four more co-located conferences besides TAP: FMICS (Formal Methods in Industrial Critical Systems), LOPSTR (In ternational Symposium on Logic-based Program Synthesis and Transformation), PPDP (International Symposium on Principles and Practice of Declarative Pro gramming), and FACS (International Conference on Formal Aspects of Compo nent Software. The 7 full papers together with 1 short paper included in this volume were carefully reviewed and selected from 14 submissions. TAP's scope encompasses many aspects of verification technology, including foundational work, tool development, and empirical research.