Oplurus cyclurus, also known commonly as the Madagascar swift and Merrem's Madagascar swift, is a species of lizard in the family Opluridae.

Its breeding is timed with the rainy season.

Both species have a distinctive large spiny tail, and neither has a dorsal crest.

Oplurus cyclurus has a dark brown or black band around the neck and similar paler markings on its back.

O. cyclurus is mostly arboreal, living in the spiny forests of southern and southwestern Madagascar.