Swainsona unifoliolata is a species of flowering plant in the family Fabaceae and is endemic to Central Australia.

It is an erect or ascending perennial plant, usually with one leaflet and racemes of about 4 to 15 purple flowers.

Swainsona unifoliolata is an erect or ascending perennial herb up to 30 cm (12 in) high with leaves 10–70 mm (0.39–2.76 in) long with a single leaflet, or occasionally 3 leaflets, the leaflets egg-shaped, mostly 10–26 mm (0.39–1.02 in) long and 5–15 mm (0.20–0.59 in) wide.

[3] Swainsona unifoliolata was first formally described in 1874 by Ferdinand von Mueller in his Fragmenta Phytographiae Australiae.

[6] This species of pea grows on gypsum or limestone on salt flats and the edges of salt lakes in the Avon Wheatbelt, Central Ranges, Gibson Desert, Great Sandy Desert, Great Victoria Desert, Little Sandy Desert, Murchison, Pilbara and Tanami bioregions of inland Western Australia, South Australia, and Finke, Great Sandy Desert, MacDonnell Ranges, Simpson Strzelecki Dunefields and Tanami bioregions of southern Northern Territory.