The Ninth International Conference \Concept Lattices and Applications (CLA 2012)" is held in Fuengirola (Malaga), Spain from October 11th until October 14th 2012. CLA 2012 is aimed at providing to everyone interested in Formal Concept Analysis and more generally in Concept Lattices or Galois Lattices, students, professors, researchers and engineers, a global and an advanced view of some of the latest research trends and applications in this eld. As the diversity of the selected papers shows, there is a wide range of theoretical and practical research directions, in the eld of data and knowledge processing, such as data mining, knowledge discovery, knowledge representation, reasoning, pattern recognition, together with logic, algebra and lattice theory. This volume includes the selected papers and the abstracts of the 4 invited talks. This year there were initially 44 submissions from which 28 papers were accepted as full papers and 3 papers as short papers. We would like to thank the authors for their work, often of very good quality, the members of the program committee and the external reviewers without whose tremendous e orts this conference would not have been possible. This is evidence of the growing quality and importance of CLA, highlighting its leading position in the eld. We would like to thank the nancial support that this conference has received from the Research Promotion Programme of the Universidad de Malaga. We would also like to thank the steering committee of CLA for giving us the opportunity of leading this edition of CLA, the conference participants for their participation and support, and people in charge of the organization. Finally, we also should not forget that the conference was managed (quite easily) with the Easychair system, paper submission, selection, and reviewing, and that Jan Outrata has o ered his les for preparing the proceedings.