The square-tailed drongo-cuckoo (Surniculus lugubris) is a species of cuckoo that resembles a black drongo.

It is found along the Himalayas extending east into Southeast Asia.

The calls are series of piercing sharp whistles rising in pitch but shrill and choppily delivered.

[2] In the past, the species S. lugubris also included the subspecies dicruroides, which is now treated as a separate species, the fork-tailed drongo-cuckoo.

The square-tailed drongo-cuckoo can be easily distinguished by its downcurved beak and the white barred vent and outer undertail, and the tail only notched with slightly flared tips.