The north of Western Siberia has seen intensive economic development. Exploration and mining for mineral resources, active road and pipeline construction, urban development, and agriculture favor invasion and dispersal of alien plant species across the Subarctic region. The paper reports new records for eight alien species and hybrids previously unknown from northwest Siberia and the flora of northern Asia: Alopecurus geniculatus L., Anthyllis vulneraria L. subsp. vulneraria, Aquilegia atrata W.D.J. Koch, A. vulgaris L., Epilobium franciscanum Barbey, Galium album Mill. subsp. album, Petunia atkinsiana (Sweet) D. Don ex W.H. Baxter, Primula elatior (L.) Hill. These species were spotted in 2012–2014 in the towns of Salekhard, Nadym, Novy Urengoy, Tarko-Sale, Gubkinsky, and Noyabrsk in the Yamal-Nenets Autonomous District, Western Siberia (Russia). Species, synonyms, overall distribution, habitat preferences, and species taxonomy with remarks on identification and differentiation from the most similar taxa occurring in the study area, as well as the list of localities are presented.