The genus Delichon is a recent divergence from the barn swallow genus Hirundo, and its three members are similar in appearance with blue upperparts, a contrasting white-rump, and whitish underparts.
The common house martin has two geographical subspecies, the western nominate subspecies D. u. urbicum, and the eastern D. u. lagopodum, which was described by German zoologist Peter Simon Pallas in 1811.