Plant species belonging to the family Acanthaceae are globally known to possess various medicinal properties and have cultural and economic importance in both traditional medicine and horticulture. They are important to both animals and humans and are used as food or for ornamental purposes worldwide. Barleria is the third largest genus in the family Acanthaceae. A few of the highly important and reported species of Barleria include B. prionitis, B. cristata, B. grandiflora, and B. lupulina. The flowers, leaves, stems, roots, and seed extracts of plants belonging to this genus are rich in bioactive compounds and have exhibited significant medicinal potential for the treatment of various ailments and infections. Evidence derived from several studies has demonstrated the antioxidant, antibacterial, antifungal, anti-inflammatory, anticancer, antidiabetic, antiulcer, hepatoprotective, analgesic, antiamoebic, antihelminthic, antiarthritic, antihypertensive, antiviral properties and toxicity of extracts, in addition inhibition of acetylcholinesterase activity and biosynthesis of nanoparticles, of the plant and seed extracts of species belonging to Barleria. Studies have reported that bioactive compounds such as flavonoids, quinones, iridoids, phenylethanoid glycosides, the immunostimulant protein “Sankaranin”, and antibiotics isolated from Barleria species are resposnsible for the above biological activities. Traditionally, the genus Barleria has significant medicinal potential; however, there is a scarcity of information on various species that are yet to be evaluated. This review provides a comprehensive report on existing literature, concerning the phytochemistry and biological activities of the genus Barleria.