The increasing prevalence of multidrug-resistant bacteria such as Escherichia coli and Salmonella spp. has heightened the search for novel antimicrobial alternatives. This study explored the phytochemical constituents and antibacterial activity of Nelsonia canescens, a plant widely used in traditional medicine. Fresh leaves and flowers were obtained from Tudun Wada Market in Gusau, Zamfara State, Nigeria, and extracted using ethanol and water. Bacterial isolates, collected from the Microbiology Laboratory at Federal University Gusau, were characterized through colonial morphology and verified using standard biochemical techniques. Phytochemical screening identified the presence of alkaloids, saponins, flavonoids, tannins, phenols, and glycosides in both aqueous and ethanolic extracts, while quinones were found only in the ethanolic flower extract. Antibacterial activity was evaluated through agar well diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays. Ethanol extracts consistently exhibited stronger antibacterial effects compared to aqueous extracts. The maximum inhibition zone (22 mm) was observed against Escherichia coli at 200 mg/ml with ethanol leaf and flower extracts, whereas aqueous extracts produced slightly lower activity (20 mm). A statistically significant result (p = 0.0003) validated the potency of the extracts.