The common European planthopper Conomelus anceps (Germar) is reported from the Avalon Peninsula of Newfoundland, Canada, and Washington State, U.S.A., as the first North American records of this delphacid. Nymphs and adults were found in Newfoundland at 16 localities on common or soft rush, Juncus effusus ssp. effusus L., and at a site in Washington on J. effusus ssp. pacificus (Fernald & Wiegand) Lint ex Zika (Juncaceae). Although the distributional status is equivocal, we consider C. anceps an immigrant in Newfoundland and the Pacific Northwest. Also newly recorded for the Atlantic provinces of Canada are the Nearctic planthopper Phyllodinus nervatus Van Duzee, collected from common hairgrass, Deschampsia flexuosa (L.) Trin. (Poaceae); the Holarctic Megamelus flavus Crawford, which was found on the sedge Carex buxbaumii Wahlenberg (Cyperaceae); and the Nearctic Muellerianella laminalis (Van Duzee), swept from grasses. Pissonotus basalis Van Duzee, a Nearctic delphacid known previously in the Atlantic provinces from Nova Scotia, was found on Aster novi-belgii L. (Asteraceae). Diagnoses, brief descriptions, and habitus photographs of the adults are provided to facilitate identification of these delphacids.