The purpose of this book is to provide reference material that includes current developments along with a future outlook on the topic. It is divided into two sections; “Morphological Overview and Extraction Prospects” and “Trends and Applications”. Part I contains four chapters that provide an overview and systematically discuss the physical morphology, suitability and extraction aspects of lichens and their secondary metabolites. Part II includes eight chapters that give in-depth insights on recent and valuable applications of lichen and their obtained products in several applied sectors, including ethnopharmacology, therapeutics, paper and dye, nutraceuticals, cosmetics, herbal industries, etc.