Background: Bruguiera gymnorrhiza L. (family Rhizophoraceae) is a true mangrove habitat in Indian Sunderban and traditionally uses for liver disorders. Objectives: The aim was to evaluate antioxidant and hepatoprotective actions of leave extract of B. gymnorrhiza L. Materials and Methods: Hydro‑methanolic extract of mangrove leaves (BR) was standardized using spectrophotometric and high‑performance thin layer chromatography methods. Radical scavenging activities were assessed in different in vitro methods, like 1,1‑diphenyl‑2‑picrylhydrazyl, 2,2’‑azino‑bis‑3‑ethyl benzthiazoline‑6‑sulphonic acid+, superoxides, nitric oxides and hydroxyl radicals. Hepatoprotective efficacy of BR (125 mg/kg and 250 mg/kg, p.o) was measured in D‑galactosamine (GalN) induced (200 mg/kg, i.p) hepatitis in Wistar rats. Silymarin (25 mg/kg, p.o) was used as known hepatoprotective agent. Results: Polyphenols such as gallic acid, quercetin, and coumarin obtained from BR exhibited powerful antioxidant properties. Moreover, it produced dose‑dependent protection against GalN induced hepatitis in rats. It significantly reduced GalN induced elevation of enzymes (alanine transaminase, aspartate aminotransferase, and alkaline phosphatase) in serum and resist oxidative stress marked by lipid peroxides, glutathione, and catalase in hepatic parenchyma. Conclusions: Polyphenols rich B. gymnorrhiza L. leaves ameliorate hepatic tissue injury through its antioxidant effects.