Banksia prolata is a shrub endemic to Western Australia. It was known as Dryandra longifolia until 2007, when all Dryandra species were transferred to Banksia by Austin Mast and Kevin Thiele. As the name Banksia longifolia had already been published as a nomen nudum, Mast and Thiele were forced to choose a new specific epithet; their choice, "prolata", is from the Latin prolatus ("elongate"), in reference to the long, narrow leaves already described by longifolia.