This volume brings together two complementary perspectives on natural products, highlighting the chemical diversity and biological significance of metabolites derived from selected plants and fungi. It provides an integrated overview of plant and fungal natural products, emphasizing their relevance to food, health, traditional medicine, biotechnology, and future pharmaceutical research. The first chapter examines essential oils from selected Mediterranean medicinal and aromatic plants belonging to the Apiaceae, Lamiaceae, and Myrtaceae plant families. It discusses their major volatile constituents, including terpenes, phenylpropanoids, and oxygenated compounds, and reviews their antioxidant, antimicrobial, anti-inflammatory, cytotoxic, and other health-related biological activities, with attention to clinical studies where available. The second chapter surveys pigments and related metabolites produced by macromycetes, with selected coverage of slime molds, mycelial cultures, and important fungal compounds. Spanning the literature from January 2010 to April 2026, it presents these compounds according to their proposed biosynthesis origins and addresses their isolation, structural characterization, biological activity, and synthesis.