Background: MimusopselengiLinn.(ME) has been traditionally utilized for its antianxiety, cytotoxic, antimicrobial, and antioxidant properties. It is also used in cancer treatment and serves as a diuretic, antiinflammatory, anti-HIV, and hypotensive agent. This study aims to assess the antidepressant activity of unripe fruits of Mimusopselengi Linn. in a mouse model of depression. Materials and Methods: Methanol extraction was conducted on unripe fruits of Mimusopselengi Linn. using a soxhlet apparatus. Mice were divided into five study groups a Normal Group, a Depression-Induced Control Group without treatment, a Standard Group (Imipramine,10 mg/kg,i.p) ,Mimusopselengi (200 mg/kg,p.o) and Mimusopselengi (400 mg/kg,p.o) for 21 days. Immobilization time was recorded in seconds and evaluated using the Tail Suspension Test (TST) and Forced Swimming Test (FST). Additionally, the total phenol and total flavonoid contents of the extracts were measured. Furthermore, various biochemical parameters, including cortisol levels, glutathione (GSH), superoxide dismutase (SOD), and catalase, were assessed. Subsequently histopathological studies were also carried out in all the studied groups. Result:The total phenolic content and total flavonoid content were found to be 3.64 μg/ml,2.56 μg/mlrespectively. Other phytoconstituents such alakaloids, tannins, flavanoids, glycosides, steroids were also detected in the extract using qualitative analysis methods. The elevated levels of phenols and flavonoids are believed to contribute to the antidepressant effects observed, comparable to the standard antidepressant imipramine. In comparison to the standard, the 400 mg/kg test of (ME) was found to be more effective in reducing immobility time in both the FST and TST respectively. Furthermore, depressed mice exhibited higher cortisol levels compared to the standard and test groups. However, the 400 mg/kg of (ME) test dose significantly lowered cortisol levels in depressed mice compared to both the standard and the 200 mg/kg of (ME) test dose. Moreover, In histopathological study it was found that a pyramidal cells in hippocampus area were degenerated in depressed brain as compared to standard and treatment. Conclusions:The study highlights the therapeutic potential of Mimusopselengilinn unripe fruits as antidepressant and antioxidant activity. These findings underscore the importance of natural products as potential therapeutic agent in the management of depression.