Lasionycta secedens is a moth of the Noctuidae family. It has a Holarctic distribution. North American populations are distributed from Labrador, northern Manitoba, and Alaska, southward to northern Maine, northern Minnesota, and south-central British Columbia. Subspecies bohemani occurs in northern Eurasia, Alaska and Yukon. It is found in boreal forest, especially bogs, and is both diurnal and nocturnal.