This book is intended to provide researchers and graduate students with a clear and thorough presentation of the recent advances in continuum damage mechanics for metals and metal matrix composites. Emphasis is placed on the theoretical formulation of the different constitutive models in this area. However, sections are added in the book to demonstrate the applications of the theory. A chapter is also included on experimental investigations and comparisons with theoretical predictions. In addition, some sections contain new material that does not appear before in the literature. Although the book covers damage mechanics in metals, the presentation is very minimal and many approaches to this topic are only briefly presented. This is mainly because there are other books that give a more thorough and adequate exposition to this subject. However the book goes in more details into the subject of damage mechanics in metal matrix composites. The primary reason for this is that no such book currently exists on this topic. Most of the available books that were published recently on this topic are edited books. This is the first book that attempts to bring together continuum damage mechanics and metal matrix composites in a single and unified volume. Therefore, a substantial part of the material reflects the authors' own work in this area, but other approaches are presented when they are clearly relevant to the topic under discussion.