Phenolic compounds have received considerable attention from the scientific community due to their presence in plants and other natural sources, as well as their antioxidant, antimicrobial, and anti-inflammatory properties, which have led to increasing interest in functional foods, the pharmaceutical sector, agriculture, and sustainable materials. This book presents the reader with several chapters on the most recent achievements in the extraction, identification, and application of phenolic compounds from natural sources. It explores both conventional and emerging technologies, such as green extraction methods and nanotechnology, while addressing challenges related to bioavailability, stability, and industrial integration. The book presents an integrated approach to transforming agro-industrial by-products into high-value, phenolic-rich ingredients, with a specific focus on modern extraction technologies, eco-friendly preparative processes, and a promising perspective for applications. Provided by leading experts from a broad spectrum of disciplines, including natural product chemistry, food science, biotechnology, and applied sustainability, this book is an excellent tool for researchers, students, and professionals seeking to understand the diverse and effective bioactive compounds and their emerging applications in various industries.