The Southern Moreton Bay Islands, abbreviated as SMBI, also known as the Bay Islands, are the four inhabited southern Moreton Bay islands located in South East Queensland, Australia. The group is part of the Redland City with a permanent population of 7,635 as of the 2021 census. However, nearly one-third of all dwellings on the islands were unoccupied, suggesting a high proportion of "second homes" that are owned by people who were elsewhere on the night of the census.