(1986) Swainsona tenuis is a species of flowering plant in the family Fabaceae and is endemic to western continental Australia.

It is a prostrate perennial herb with many stems, imparipinnate leaves with 5 to 9 egg-shaped leaflets with the narrower end towards the base, to linear or elliptic leaflets, and racemes of up to 7 purple flowers.

Swainsona tenuis is a prostrate perennial herb that typically grows to a height of up to about 30 cm (12 in), and has many hairy stems.

[2][3] Swainsona tenuis was first formally described in 1904 by Ernst Georg Pritzel in the Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie from specimens collected in 1902.

[6] This species of pea grows in sandy soil or on stony flats near creeks and rocky places in the Central Ranges, Coolgardie, Gascoyne, Gibson Desert, Great Victoria Desert, Little Sandy Desert, Murchison and Nullarbor bioregions of Western Australia, western South Australia and in the south-western part of the Northern Territory.