The cosmopolitan, Jurassic to Recent, bivalve Acesta (Limidae) is documented from Australian Cretaceous (upper Albian) rocks in the lowermost section of the Mackunda Formation of Queensland. These specimens from Landsborough Downs, Flinders Shire, represent an endemic new species, herein named Acesta (Acesta) backae n. sp. Acesta (A.) backae n. sp. was a shallow-water suspension feeder that inhabited the Cretaceous Australian epicontinental sea of the Great Artesian Basin. Although hinge details of Acesta (A.) backae n. sp. are wanting, this new taxon is most closely allied with Acesta? sp. of the Miria Formation of Western Australia and can clearly be discriminated from other Cretaceous Austral forms.