It feeds on insects which are caught in flight, and it migrates to climates where flying insects are plentiful. It has a blue head and upperparts, white rump and pure white underparts, and is found in both open country and near human habitation

The adult common house martin is 13 cm long, with a wingspan of 26–29 cm and a weight averaging 18.3 grams. It is much more urban than the barn swallow, and will nest even in city centres if the air is clean enough

The common house martin is a noisy species, especially at its breeding colonies. The male's song, given throughout the year, is a soft twitter of melodious chirps. The nest is a neat closed convex cup fixed below a suitable ledge, with a narrow opening at the top. It is constructed by both sexes with mud pellets collected in their beaks, and lined with grasses, hair or other soft materials.