Virulent diseases continue to cause millions of global deaths annually, exacerbated by the growing issue of microbial resistance, which casts uncertainty on the future use of antimicrobial drugs. Catharanthus roseus (Periwinkle or Sadabahar), a medicinal plant belonging to the Apocynaceae family, is abundantly found in tropical regions and is rich in phytochemicals. The leaves of C. roseus are commonly used in traditional medicine for the treatment of various critical illnesses. This research aims to explore the phytochemical composition and antimicrobial activity of both aqueous and methanolic extracts of C. roseus leaves. The study evaluated the presence of key phytochemicals such as flavonoids, glycosides, phenols, saponins, tannins, terpenoids, and steroids, alongside testing the antibacterial potential of the extracts. The extracts were tested against four common bacterial strains using the agar well diffusion method, with Ciprofloxacin serving as the standard control. The results revealed that the aqueous extract exhibited the highest antibacterial activity, with a zone of inhibition of 55 ± 0.6 mm against Staphylococcus aureus (S. aureus), followed by 45 ± 0.3 mm against Salmonella enterica. The methanolic extract also showed significant antibacterial activity, with a zone of inhibition of 40 ± 0.2 mm against S. aureus. Conversely, the methanol extract showed the smallest inhibition zones against Bacillus subtilis (24.0 mm) and Escherichia coli (E. coli) (25.0 mm). Phytochemical analysis of methanolic extract revealed the presence of glycosides, flavonoids, phenols, tannins, steroids, saponins, and terpenoids. These findings confirm the promising antimicrobial efficacy of both the methanolic and aqueous extracts of C. roseus, particularly against E. coli, S. aureus, S. enterica, and B. subtilis. The study supports the therapeutic potential of C. roseus as a valuable medicinal resource and eco-friendly alternative for combating microbial infections and producing value-added products, including treatments for complex diseases such as cancer.