Common in woodland, plantations, scrub, gardens and parks throughout the British Isles. Widespread and common in Hampshire and on the Isle of Wight. Wingspan 50-64 mm. The main confusion species is Lesser Swallow Prominent P. gnoma
, in which the thin white tornal line of Swallow Prominent is replaced by a very distinct white, wedge-shaped dash. Larva feeds on Aspen, Poplar, Willow and Sallow, over-wintering as a pupa.