ABSTRACT Fifty-three new species of benthic foraminifers and four new genera have been formally named from the Cenomanian to Miocene sequences of the Beaufort-Mackenzie Basin of Arctic Canada. The new species consist of 36 agglutinated walled foraminifers and 17 calcareous. The new taxa belong to the families Haplophragmoididae, Discamminidae, Cyclamminidae, Trochamminidae, Verneuilinidae, Globotextulariidae, Spiroloculinidae, Hauerinidae, Bolivinidae, Turrilinidae, Stainforthiidae, Siphogenerinoididae, Bagginidae, Parrelloididae, Epistomariidae, Asterigerinatidae, Nonionidae, Heterolepidae, and Elphidiidae. The Beaufort-Mackenzie Basin is located on the cratonic margin of North America bordering the Arctic Ocean and contains 12 to 16 km of Upper Cretaceous to Cenozoic terrigenous clastic sediments. Planktonic foraminifers are absent through the entire section, and therefore benthic foraminifers have added significance for biostratigraphic analysis. Fifteen interval zones, defined from the last occurrences of benthic foraminifers, have been recognized in these strata. Ten of the new taxa are indices in this interval zonation and new names replace the open nomenclature that was previously used. All 53 new species are significant for biostratigraphic zonation, depositional sequence analysis, and other basinal studies in the Beaufort-Mackenzie and neighbouring Arctic regions. Many of the species have restricted environmental ranges and are important for paleoenvironmental reconstruction.