The pearl-breasted swallow (Hirundo dimidiata) is a small swallow.
The pearl-breasted swallow is 13–14 cm long. It has glossy blue upperparts and grey-white underparts. The upper wings, underwing flight feathers and forked tail are blackish-blue. The underwing coverts are a darker shade of grey-white. The lack of white in the tail is a distinction from similar Hirundo species. The outer feathers are slightly longer in the male than the female. Juveniles are duller and browner than the adult, with shorter outer tail feathers. The northern subspecies, H. d. marwitzi is darker and smaller than nominate H. d. dimidiata, but the differences are small, and the species may be monotypic.