氨苄青霉素（Ampicillin），又称安比西林、氨苄西林，是一种β-内酰胺类抗生素。

氨苄青霉素属于氨基青霉素类。氨基青霉素也包含了阿莫西林（Amoxicillin），他们比青霉素或耐青霉素酶青霉素（penicillinase-resistant penicillins）更易穿透革兰氏阴性菌，不过易被细菌β-内酰胺酶（Beta-lactamase）分解，因此常搭配舒巴坦（一种β-内酰胺酶抑制剂）一起使用以加强对可产生β-内酰胺酶细菌的治疗效果。

氨苄青霉素主要使用于治疗细菌感染如中耳炎、鼻窦炎及急性细菌性膀胱炎等。和阿莫西林相比，口服氨苄青霉素生物利用度较低，且易产生肠道副作用。

Ampicillin is an antibiotic used to prevent and treat a number of bacterial infections. This includes respiratory tract infections, urinary tract infections, meningitis, salmonella infections, and endocarditis. It may also be used to prevent group B streptococcal infection in newborns. It is used by mouth, by injection into a muscle, or intravenously. Like all antibiotics, it is not useful for the treatment of viral infections.