Thunbergia, a genus under the family Acanthaceae, is known for important medicinal plants that, in general, exhibit antibacterial, antifungal, antioxidant, anti-inflammatory, and hepatoprotective activities. The present study aims to investigate antioxidant activities in alcoholic and aqueous plant extracts using ABTS (2,2 -Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric ion reducing antioxidant power) for free radical scavenging activity and evaluation of total content of phenolics, flavonoids and ascorbate. The current study is performed in the leaves and stems of Thunbergia alata, Thunbergia erecta, and Thunbergia mysorensis due to their easy availability in the Indian subcontinent and unexplored nature. The highest amount of phenolics and flavonoids was recorded in the leaves and stem of T. alata. In contrast, the highest ascorbate was recorded in T. erecta leaves and T. mysorensis stem. Interestingly, in aqueous extracts, T. erecta performed the best in FRAP assay in both leaves and stem segments; T. alata stem and T. mysorensis leaves performed well in ethanolic extract. Ethanolic extracts of T. alata and T. mysorensis leaves performed better for DPPH assay, while T. erecta stems performed better in aqueous extract. ABTS assay was exceedingly high in the ethanolic extract of T. alata stem and contrastingly low in T. erecta aqueous and ethanolic extract. Looking at the values, FRAP appears sensitive in depicting stark differences in leaves and stem parts in aqueous or ethanolic extracts. Thus, the present investigation suggests that the studied plant has an accessible source of antioxidants for medicinal and commercial purposes.