"Banksia brownii" was first collected near King George Sound in 1829 by William Baxter, who named it in honour of botanist Robert Brown. A formal description was published by Brown in his 1830 "Supplementum Primum Prodromi Florae Novae Hollandiae"; thus the full botanic name of the species is "Banksia brownii" Baxter ex R.Br. Under Brown's taxonomic arrangement, "B. brownii" was placed in subgenus "Banksia verae", the "true banksias", because its inflorescence is a typical "Banksia" flower spike. "Banksia verae" was renamed "Eubanksia" by Stephan Endlicher in 1847.