The present study evaluates the antibacterial efficacy of ethanolic extracts from <em>Delonix regia</em> leaves against diarrhea-inducing bacteria <em>Escherichia coli</em> and <em>Salmonella typhimurium</em>. Preliminary phytochemical screening revealed that <em>D. regia</em> leaves comprise flavonoids, alkaloids, saponins, tannins, phenolics, and terpenoids. Fourier Transform Infrared Spectroscopy (FTIR) analysis identified various functional groups in the <em>D. regia</em> leaf extract, including O-H, C-H, C=O, C=C, C-C, C-O, and C-O-C. Liquid Chromatography-Mass Spectrometry/Mass Spectrometry (LC-MS/MS) analysis further confirmed the presence of 16 distinct compounds comprising amino acids, alkaloids, phenolics, flavonoids, terpenoids, anthraquinones, n-acyl pyrrolidines, and fatty acids. The disc diffusion method (Kirby-Bauer) was employed for the antibacterial tests. The extracts of <em>D. regia</em> leaves at concentrations of 25%, 50%, 75%, and 100% generated inhibition zones measuring 5.26 mm, 6.37 mm, 7.27 mm, and 10.18 mm against <em>E. coli</em>, and 5.05 mm, 7.01 mm, 8.77 mm, and 10.04 mm against <em>S. typhimurium</em>, respectively. The commercial antibiotic ciprofloxacin (a positive control) produced inhibition zones of 30.02 mm for <em>E. coli</em> and 28 mm for <em>S. typhimurium</em>. The negative control, consisting of 10% ethanol, showed no inhibitory effect on bacterial growth. These findings indicate that the ethanolic extract of <em>D. regia</em> leaves possesses antibacterial properties against <em>E. coli</em> and <em>S. typhimurium</em>. It is likely that secondary metabolite compounds, such as flavonoids and phenolics, contribute significantly to the observed antibacterial activity