Ultrafine-grained (UFG) materials are defined formally as those materials having grain sizes smaller than 1 μm, thereby including both submicrometer grain sizes where the size is within the range of 100 nm to 1.0 μm and true nanostructured materials where the grain size is below 100 nm. These materials have attracted, and are continuing to attract, considerable interest within the materials science community, mainly because they offer the potential for achieving both high strength and a superplastic forming capability. There are now several conferences and symposia organized each year devoted specifically to these materials but there are also other more general meetings where UFG materials are not the main objective but nevertheless they represent an important topic within the overall proceedings of the meeting. The initiative for organizing this Special Section of Advanced Engineering Materials arose from our participation at two different important conferences. The first was the International Baikal Materials Science Forum which was held on July 9-15, 2018 in the Republic of Buryatia (Ulan-Ude and Lake Baikal, Goryachinsk village) in Russia and the second was the 13th International Conference on Superplasticity in Advanced Materials (ICSAM-2018) which was held in Saint Petersburg in Russia on 19-22 August, 2018. At both meetings it was clear that there were many new and interesting developments associated with the topic of UFG materials and the suggestion evolved of inviting several of the major participants at these two meetings to prepare papers for publication in a Special Section of this journal. Invitations were sent out and it is a pleasure to report that they were received enthusiastically by all participants. Accordingly, a collection of papers was assembled for this Special Section covering some of the newer topics within the fields of UFG materials and their associated coatings. The present collection also marks the 10th anniversary of Advanced Engineering Materials Special Issue that was published in 2010 (No 8) with the focus on research of fundamental aspects of nanostructuring of metals and alloys and demonstration of their high innovation potential, thus attracting much interest and high citation frequency in materials science community. This issue continues the discussion of innovation applications of UFG materials. We are grateful to Dr. Sandra Kalveram, Editor-in-Chief of Advanced Engineering Materials, for accepting our proposal for this Special Section and for assisting and coordinating the various papers. We also express our very special thanks to Dr. Elena V. Bobruk of the Institute of Physics of Advanced Materials at Ufa State Aviation Technical University for providing much assistance in communicating with authors, arranging the reviews of manuscripts and for ensuring that all tasks were completed on time. We acknowledge with thanks the authors who accepted our invitation to participate in this Special Section and we are especially grateful that all papers were received within the appropriate deadlines.