The study evaluated the volatile and bioactive constituents of ethanol extracts of Justicia secunda using gas chromatography-mass spectrometry (GC-MS) for volatile composition while bioactive compound were assessed using gas chromatography flame ionization detector (GC-FID). The leaf extracts were prepared by being collected, air-dried, macerated in 96% ethanol, filtered and concentrated at 450C. The result obtained revealed the presences of bioactive compound such as flavonoid that include: Spartein (28.10 µg/ml), Ruti (15.6 µg/ml), Oxalate (12.70 µg/ml), Naringin (12.4 µg/ml), Steroids (11.7 µg/ml), Epinedrine (11.10 µg/ml), Cardiac glycoside (10.10 µg/ml), Flavonone (10.10 µg/ml), Ribalinidine (9.30 µg/ml), Anthocyanin (7.70%), Flavone (7.30 µg/ml), Sapogenin (7.30µg/ml), Proanthocyanin (6.90 µg/ml),Resveratol (6.70µg/ml), Epicatechin (5.70 µg/ml), Phytate (5.70µg/ml), Kaempferol (3.90 µg/ml),Catechin (2.00 µg/ml), Tannin (2.00 µg/ml). The GC-MS Screening of the plant’s extract identified eighty-two (82) bioactive compounds, which include Ethyl palmitate (5.54%), 2,4-Di-tert-butylphenol (4.04%),9,17-Octadecadienal, (4.05%), Linoleic acid ethyl ester (4.05%), 9,12-Octadecadienoic acid, ethyl ester (4.00%), Decane, 2-methyl (3.82%), Hexadecane (3.82%), Heptadecane, 2,6-dimethyl (3.26%), N-(3-methylButyl) acetamide (3.02%), Sulfurous acid, butyl octyl ester (3.25%), Hexane,1-(hexyloxy)-5-(3.06%) as the major bioactive compounds. The result of the GC-MS analysis showed that the ethanol extract of Justicia secunda contains many pharmacologically important bioactive compounds such as antioxidant, anti-inflammatory, anti-microbial, anti-diabetic anti-cancer effects. Traditionally, Justicia species are used in the treatment of inflammation, rheumatism, arthritis gastrointestinal diseases, anaemia and respiratory tract infection. The proximate analysis of the ethanol extract of the leaves revealed notable levels of various components, where carbohydrates were found to be the highest, followed by moisture content, protein, fats, fiber, and ash content, respectively.