Banana fruit peel is commonly regarded as an agricultural waste product; however, it is a rich source of biologically active phytochemicals with potential therapeutic applications. Banana peels contain several important bioactive compounds such as phenolic compounds, flavonoids, tannins, and catecholamines, which exhibit strong antioxidant properties. These compounds may play an important role in protecting against oxidative stress–related gastrointestinal disorders. Gastric ulcer is a widespread gastrointestinal disease and remains a significant global health concern. It is commonly associated with factors such as excessive alcohol consumption, prolonged use of non-steroidal anti-inflammatory drugs (NSAIDs), infection with Helicobacter pylori, and psychological stress. Oxidative stress is known to contribute significantly to gastric mucosal damage, highlighting the importance of antioxidants in ulcer prevention and treatment. The present study was designed to comparatively evaluate the phytochemical composition, antioxidant activity, and gastroprotective potential of banana peel extracts obtained from selected banana varieties. Peels from three commonly available species, namely Musa acuminata, Musa paradisiaca, and Musa balbisiana, were collected and shade dried. The dried peels were powdered and extracted using Soxhlet extraction with methanol and ethanol as solvents. Preliminary qualitative phytochemical screening was performed to identify major secondary metabolites, while quantitative estimation of total phenolic and flavonoid content was carried out using standard methods. The antioxidant activity of the extracts was assessed using DPPH, ABTS, and FRAP assays to determine their radical scavenging and reducing capacities. Gastroprotective activity was evaluated using an ethanol-induced gastric ulcer model in experimental animals, where parameters such as ulcer index, gastric pH, and mucus content were measured. The findings revealed that banana peel extracts contain significant amounts of phenolic and flavonoid compounds and exhibit strong antioxidant activity. Additionally, the extracts significantly reduced gastric ulcer formation compared with the ulcer control group. These results suggest that banana peel extracts possess promising antioxidant and gastroprotective properties and may serve as potential natural agents for the development of anti-ulcer therapies.