Dillwynia tenuifolia is a rare plant endemic to New South Wales. It is a member of the tribe Mirbelieae which are known for their golden pea-shaped flowers. D. tenuifolia is a small shrub, to 1 metre, it produces orange-yellow and red pea-flowers It is found around Sydney, on the Cumberland Plain from Windsor to Penrith east to Deans Park. Other populations in western Sydney are recorded from Voyager Point and Kemps Creek, Ludenham, South Maroota. Other populations are known from the Bulga Mountains, Kurrajong Heights and Woodford in the Lower Blue Mountains.