We present the first record of Aegolius harrisii (Cassin, 1849) from the state of Maranhão, extending the known distribution of the species 283 km to the west in the Brazilian Northeast. This record also represents the northernmost locality of the species within the Cerrado phytogeographic domain, which coincides with the ecotone between the Cerrado, Caatinga, and Amazon domains. Given the considerable gaps in the data on the occurrence of this owl in the Brazilian Northeast, we would recommend more surveys in specific areas with similar phytophysiognomies.