Drosera derbyensis is a perennial carnivorous plant in the genus Drosera and is endemic to Western Australia. Its erect or semi-erect leaves are arranged in a rosette with one or more rosettes emerging from the root stock. The petioles are narrowly oblanceolate, 0.8–1.0 mm wide at the proximate end and 1.3–1.7 mm wide at the apex, narrowing to 0.5–0.7 mm at the laminar base. The petioles are frequently 35–45 mm long when the plant is in flower and are covered in white woolly non-dendritic hairs. The insect-trapping leaf lamina is orbicular and much shorter than the petioles at only 2–3 mm in diameter. The laminar adaxial surface is covered in insect-trapping glands. Each rosette produces 1–4 raceme inflorescences, which are 25–35 cm (10–14 in) long. Each inflorescence bears 30–50 white flo