This book constitutes the refereed proceedings of the 18th International Conference on Bioinformatics and Computational Biology, BICOB 2026, held in Honululu, Hawaii, USA, during March 23&March 25, 2026. The 21 full papers presented in this book were carefully reviewed and selected from 38 submissions.The conference covered a wide range of bioinformatics and computational biology topics, including bioinformatics algorithms, computational proteomics, genomics, structural bioinformatics, graph and machine learning applications in bioinformatics, as well as medical and healthcare informatics.