Dillwynia laxiflora was first described in 1837 by George Bentham in Charles von Hügel's Botanisches Archiv der Gartenbaugesellschaft der Ossterreichischen Kaiserstaates. The specific epithet means "wide or open-flowered".
Distribution and habitat
This dillwynia grows in sandy or gravelly soils on hillcrests in the south-west of Western Australia.