Orthosia Ochsenheimer, 1816 is a Holarctic-Oriental noctuid genus comprising more than 60 described species, with most distributed in the eastern and southeastern Palaearctic and Oriental regions. Many species have recently been described from Asia (Hreblay 1991, 1993, 1994; Yoshimoto 1993; Hreblay & Plante 1994; Hreblay & Ronkay 1998, 1999; Ronkay et al. 2010, Saldaitis et al. 2011, etc.). The O. incerta species-group includes 10 described species (see Ronkay et al. 2001), and during the course of faunistic studies on the Noctuidae of North-East Kazakhstan, a new member of this species-group was found; it is described herein as new.