蝙蝠科（学名Vespertilionidae）是哺乳动物翼手目下小翼手亚目的一科，全世界约有300多种，大部分原产于欧洲和北美。

几乎所有蝙蝠科的种类都以昆虫为食，部分鼠耳蝠属(Myotis)和食鱼蝠属(Pizony)会捕鱼，山蝠属(Nyctalus)会捕捉燕雀类的鸟类。

Vesper bats (family Vespertilionidae), also known as evening bats or common bats, are the largest and best-known family of bats. They belong to the suborder Microchiroptera (microbats). Over 300 species are distributed all over the world, on every continent except Antarctica. It owes its name to the Latin word vespertilio ("bat"), from vesper, meaning "evening".