Phenolics or phenolic compounds (PCs) have been acknowledged as innumerable secondary metabolites (SM) and directed as highly pervasive, distinct, and incalculable phytochemicals, ranging from simple molecules to highly complex polymerized substances. Most plant tissues, including fruits and vegetables, encompass phenolic compounds and represent principal source for various functional activities. Around, 9000 phenolics have been reported in different scientific literatures, with approximately half of them being identified as flavonoids. The well-established botanical features, biosynthesis, idiosyncratic phytochemistry, and diversified pharmacological, phytoestrogenic, insecticidal, ultraviolet stabilizers, antioxidant, and free radical scavenger activities have placed the PCs at a station where these natural molecules find a vast application in pharmaceutical and nutraceutical industries, food and beverage, personal care manufacturing, and textile and packaging industries. However, regardless of many botanical, phytochemical and pharmacological reviews and studies on the topic, certain matters still necessitate to be scrutinized and addressed which requires extensive and targeted studies on the subject. In view of the importance of secondary metabolites and their applications, this chapter has been inscribed to accommodate the distinctive attributes of phenolic compounds, their role from phytochemistry and pharmacological stans, filling the gap and extending new opportunities from botanicals to find better therapeutic products by combining two or more molecules, delivering the products in a most suitable pharmaceutical dosage, and immediate or modified release form to handle and support global and regional health care issues. In addition, the chapter also encompasses structural and functional corelations linked with some of the most popular phenolics available globally for various pharmaceutical, nutraceutical, and industrial applications.