The serotine bat (latin Eptesius serotinus), also known as the common serotine bat, big brown bat, or silky bat is a fairly large Eurasian bat. It is widespread throughout continental and Mediterranean Europe, as far as England and southern Sweden. It also occurs in the Middle East and the Caucasus, up to the Himalayas.

It prefers open areas with scattered trees, crops, inhabited areas, and wetlands, whereas, it avoids dense forests. It takes refuge in tree hollows, rock crevices, and cave entrances; but mainly in human structures (houses, bridges, artificial shelters).