Orchid is a large family of flowering plants, which belong to genus Orchidaceae. Orchid plants produce complex flowers having a large specialized lip (labellum). Most of the orchids are perennial. They are found in terrestrial and epiphytic habitats. Orchid phytochemistry refers to the study of phytochemicals or the chemicals derived from orchid plants. Some of the common phytochemicals detected in orchids are alkaloids, phenols, flavonoids, tannins and proteins. Orchid research focused on the biology of orchids involves the cellular and molecular processes of orchid plants such as pigment and floral scent formation, pollination, bioactive compounds, and plant-microbe interactions in orchid species. This book includes some of the vital pieces of works being conducted across the world, on various topics related to orchids. Its extensive content provides the readers with a thorough understanding of the phytochemistry and biology of orchids. The book will prove to be immensely beneficial to students and researchers studying this family of flowering plants.