Dendrobium cuthbertsonii is a species of orchid in the genus Dendrobium. It grows epiphytically at up to 10,000 feet (3,000 m) above sea level in New Guinea and the Bismarck Archipelago. It is targeted by commercial collectors who harvest it for export. It has one of the longest floral durations of any orchid, with individual flowers remaining open for up to nine months. Its stems are 1–2 centimetres (0.4–0.8 in) tall and 4–7 millimetres (0.16–0.28 in) wide; the flowers are 25–40 mm (1.0–1.6 in) long, 13–35 mm (0.5–1.4 in) wide, and extremely variable in colour.