This book constitutes the refereed proceedings of the 18th International Conference on Graph Transformation, ICGT 2025, held in Koblenz, Germany, during June 11-12, 2025. The 10 full papers and 1 short paper included in this book were carefully reviewed and selected from 19 submissions. The topics of the accepted papers cover a wide spectrum, ranging from advancements in the classical theory of graph transformation to the integration of artificial intelligence approaches with graph transformations, the fuzzing of graph databases, and applications of graph transformation in areas such as dialogue management systems and threat analysis.