In Tasmania, "Banksia marginata" occupies a wide range of habitats, in mixed forest (where it grows as a small tree), button grass moorlands, flood plains of the Loddon, Franklin and Huon Rivers, as well as coastal regions. In parts of the west and southwest of Tasmania, the species is dominant within the threatened native vegetation community known as "Banksia marginata" wet scrub. There is no macrofossil record for the species, so it is unclear whether it is a recent introduction from the mainland or has only recently evolved, although its presence on both the mainland and Tasmania suggests it has been present since the Pleistocene. It grows in coastal habitats that would be occupied by "Banksia integrifolia" on the mainland.