Momordica charantia is widely cultivated in Zaria, Nigeria, and holds a prominent place in traditional medicine. Its leaves, fruits, and seeds are known to be rich in bioactive compounds and are commonly employed to treat various infections and diseases. This study aimed to investigate the bioactive components and antibacterial properties of methanolic leaf extracts and their fractions. Phytochemical analysis of the methanolic extract revealed the presence of alkaloids, saponins, flavonoids, glycosides, tannins, steroids, and terpenoids. The methanolic extract was fractionated into n-butanol, ethyl acetate, and chloroform fractions. The methanolic extract exhibited superior antibacterial activity compared to its fractions, suggesting potential synergistic effects among the plant’s constituents. Antibacterial efficacy was evaluated using well-diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays. Salmonella typhi was the most susceptible bacterium, with zones of inhibition of 25.00 ± 0.10 mm, MIC of 12.5 ± 0.82 mg/mL, and MBC of 50 ± 0.22 mg/mL. This was followed by Escherichia coli (18.77 ± 0.25 mm, MIC: 50 ± 0.53 mg/mL, MBC: 100 ± 0.82 mg/mL) and Staphylococcus aureus (14.13 ± 0.91 mm, MIC: 50 ± 0.23 mg/mL, MBC: 100 ± 0.48 mg/mL). Among the fractions, the n-butanol fraction demonstrated the highest antibacterial activity. Subsequent analysis of this fraction using GC-MS identified key compounds, including 2-pentanone, 4-hydroxy-4-methyl-, n-amyl isovalerate, 2(5H)-furanone, 3,5,5-trimethyl-, furan, tetrahydro-2,2,4,4-tetramethyl-, and 3-tetradecanol acetate. In conclusion, the methanolic extract followed by n-butanol fraction of M. charantia exhibited significant antibacterial activity, particularly against Gram-negative bacteria such as S. typhi and E. coli. Further research is recommended to isolate and characterize the bioactive compounds responsible for this activity.