This book constitutes the refereed proceedings of the 13th International Conference on Formal Concept Analysis, ICFCA 2015, held in Neja, Spain, in June 2015. The 16 revised full papers presented were carefully reviewed and selected from 38 submissions. The topics in this volume cover theoretical aspects of FCA; methods and applications of FCA to different fields and enhanced FCA that show new trends in FCA, for instance, pattern structures of fuzzy FCA.