Cycas cairnsiana is a species of cycad in the genus Cycas, native to northern Australia in northern Queensland on the Newcastle Range. The stems grow to 2-5 m tall and 12-16 cm diameter, with swollen base. The leaves are dark orange-brown tomentose on emerging, then glaucous blue-green and glabrous with age, 60-110 cm long, bowed, keeled, pinnate, with 180-220 leaflets, the leaflets 8-18 cm long and 2-4 mm wide. The petioles are 18-27 cm long, and armed with sharp spines. It is named after William Cairns, governor of Queensland from 1875–1877.