This book constitutes the refereed proceedings of the 12th International Conference on Formal Concept Analysis, ICFCA 2014, held in Cluj-Napoca, Romania, in June 2014. The 16 regular papers presented together with 3 invited talks were carefully reviewed and selected from 39 submissions. The papers in this volume cover a rich range of FCA aspects, such as theory, enhanced FCA. Knowledge discovery and knowledge spaces, as well as methods and applications. In addition the book contains a reprint of the first publication "Sub direct decomposition of concept lattices" by Rudolf Wille.