Ethnopharmacological relevance: Ormosia robusta (fabaceae) is a perennial non-climbing woody tree. Objective: The current study sought to investigate the phytochemical screening, antioxidant properties, membrane stabilizing activity, anticonvulsant activity, and gastrointestinal motility properties of O. robusta methanolic leaf extract. Materials and methods: Phytochemical analysis was carried out using standard methods, and antioxidant activity was determined using the estimation of total phenolic contents and DPPH radical scavenging activity. Hypotonic solution-induced haemolysis and Heat-induced haemolysis tests were used to investigate membrane stabilizing activity. The anticonvulsant activity was evaluated using Isoniazid (INH) induced convulsions and Pilocarpine induced convulsions methods in mice. And gastrointestinal motility test was carried out by the charcoal meal passage test in mice using methanolic leaf extract of O. robusta. Results: Preliminary phytochemical examination showed the presence of phytosterols, phenol, glycosides, tannins, terpenoids, flavonoids, saponin, protein and amino acid. The methanolic leaves extract of O. robusta (200 and 400 mg/kg; i.p.) produced significant (p < 0.01) dose-dependent inhibition of the latency of convulsion responses elicited by Pilocarpine and Isoniazid. The membrane-stabilizing action of the extract was demonstrated by its ability to prevent hypotonic and heat-induced haemolysis. Methanolic extract showed significant antioxidant properties. In respect of the gastrointestinal motility test, O. robusta caused significant (p < 0.001) dose-dependent inhibition of motility in the mice. The effects of the extract in the various models were generally comparable to those of the standard drugs used. Conclusion: The findings in this study suggest that the methanolic leaves extract of O. robusta possesses antioxidant, membrane stabilizing activity, gastrointestinal motility properties and anticonvulsant effect possibly mediated through several mechanisms. These activities could be attributed to the presence of tannins, terpenoids, phenols, saponins and flavonoids.