Thysanotus banksii is a species of flowering plant in the Asparagaceae family, and is native to Australia and New Guinea. It is a perennial herb with a small rootstock, linear leaves, and umbels of purple flowers with elliptic, fringed petals, lance-shaped sepals and six stamens.
Thysanotus banksii is a clumping perennial herb with a small rootstock, fibrous roots and 3 to 5 channelled annual leaves long and about wide. The flowers are borne in umbels of one or two flowers on a pedicel long. The flowers are purple, with perianth segments long, the sepals lance-shaped, about wide, the petals elliptic, about wide with a fringe about long. There are six stamens and the style is about long. The seed is more or less spherical, about long in diameter with a straw-coloured aril.
Thysanotus banksii was first formally described in 1810 by Robert Brown in his Prodromus Florae Novae Hollandiae. The specific epithet (banksii) honours Joseph Banks.
This species of Thysanotus grows in forest and moist tea-tree flats and on pebbly ridges from near Rockingham Bay to Cape York, the Gulf of Carpentaria in Queensland, and islands in the Torres Strait. It also occurs in southern New Guinea.
Thysanotus banksii is listed as of "least concern" under the Queensland Government Nature Conservation Act 1992.