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Baleen whales (Mysticeti) possess the necessary anatomical structures and genetic elements for olfaction. Nevertheless, the <i>olfactory receptor</i> gene (<i>OR</i>) repertoire has undergone substantial degeneration in the cetacean lineage following the divergence of the Artiodactyla and Cetacea. The functionality of highly degenerated mysticete <i>OR</i>s within their olfactory epithelium remains unknown. In this study, we extracted total RNA from the nasal mucosae of common minke whales (<i>Balaenoptera acutorostrata</i>) to investigate <i>OR</i>s’ localized expression. All three sections of the mucosae examined in the nasal chamber displayed comparable histological structure. However, the posterior portion of the frontoturbinal region exhibited notably high <i>OR</i> expression. Neither the olfactory bulb nor the external skin exhibited the expression of these genes. Although this species possesses four intact non-class-2 <i>OR</i>s, all the <i>OR</i>s expressed in the nasal mucosae belong to class-2, implying the loss of aversion to specific odorants. These anatomical and genomic analyses suggest that <i>OR</i>s are still responsible for olfaction within the nasal region of baleen whales, enabling them to detect desirable scents such as prey and potential mating partners.