Garcinia livingstonei T. Anderson (family Clusiaceae) is a rich source of different classes of bioactive compounds, mainly phenolics, which possess beneficial pharmacological activities. In the present study the methanolic extract (ME) of the leaves was analyzed using UPLC-QTOF-MS/MS technique in both negative and positive modes. Its total phenolics and flavonoids content were determined using Folin-ciocalteu and Aluminum chloride methods, respectively. Besides, the antioxidant activity of the ME and its different factions was estimated using three different assays (DPPH, FRAP and ABTS), also the antiarthritic activity was evaluated using protein denaturation, membrane stabilization and xanthine oxidase inhibitory % assays. Moreover, two different molecular docking studies were performed to investigate the potential antioxidant and antiarthritic activities of the identified compounds. UPLC-QTOF-MS/MS analysis revealed the presence of biflavonoids, benzophenones, flavonoids, xanthones, phenolic and organic acids. The total phenolics content was found to be 114.72 mg/g extract expressed as gallic acid equivalence, while the total flavonoids content recorded 53.1 mg/g extract expressed as rutin equivalence. Ethyl acetate fraction showed the most potent antioxidant and antiarthritic activities.