Chaetopterus is a globally distributed genus of marine Annelida with a long history of taxonomic confusion. Here, we describe Chaetopterus bruneli sp. nov. from a depth of 350 m in the St. Lawrence Estuary, eastern Canada. The new species represents the northernmost record for Chaetopterus in the western Atlantic to date. The similar European species Chaetopterus norvegicus M. Sars, 1835 is resurrected from long-standing synonymy and redescribed from type material, and a lectotype is designated.