Collection of moths and butterflies during 2010–2019 revealed 15 species not previously reported from the Murmansk Oblast, Russia. Revision of published data added nine more species to the regional fauna. We also confirmed records of 14 species known only from old publications, and report records of 83 infrequent species, which clarify their distribution within the study region or demonstrate interesting ecological patterns. Especially noteworthy are records of Argyresthia retinella, Levipalpus hepatariella, Araschnia levana, Macroglossum stellatarum and Endromis versicolora. We discuss the occurrence of 10 moth species in the Murmansk Oblast that had been based on erroneous or doubtful identifications, and therefore not included in our list. The known fauna of moths and butterflies of the Murmansk Oblast now totals 834 species. We estimate that the regional Lepidopteran fauna may include 1000 to 1020 species.