Local Ethiopians useCalpurnia aureato treat skin infections. However, there is no adequate scientific confirmation. The aim of this study was to evaluate the antibacterial activities of the crude and the fractionated extracts ofC. aurealeaves against different bacterial strains. The crude extract was made by maceration. The Soxhlet extraction method was used to obtain fractional extracts. The antibacterial activity against gram positive and gram negative American Type Culture Collection (ATCC) strains was performed using the agar diffusion technique. The minimum inhibitory concentration was determined through the microtiter broth dilution method. Preliminary phytochemical screening was done using standard techniques. The largest yield was obtained from ethanol fractional extract. Except for chloroform, which provided a relatively low yield when compared to petroleum ether, increasing the polarity of the extracting solvent improved the yield. The crude extract, solvent fractions, and the positive control showed inhibitory zone diameter, while the negative control did not. When used at a concentration of 75 mg/ml, the crude extract had similar antibacterial effects as gentamicin (0.1 mg/ml) and the ethanol fraction. The 2.5 mg/ml crude ethanol extract ofC. aureasuppressed the growth ofPseudomonas aeruginosa,Streptococcus pneumoniae, andStaphylococcus aureus, according to the MIC values. The extract ofC. aureawas more effective in inhibitingP. aeruginosathan the other gram-negative bacteria. Fractionation enhanced the antibacterial effect of the extract.All fractionated extracts showed the highest inhibition zone diameter againstS. aureus. Petroleum ether extract had the greatest inhibition zone diameter against all bacterial strains. The non-polar components were more active compared to the more polar fractions. The phytochemical components discovered in the leaves ofC. aureaincluded alkaloids, flavonoids, saponins, and tannins. Among these, the tannin content was remarkably high. The current results could provide a rational support for the traditional use ofC. aureato treat skin infections.