Dacalana cotys, the white-banded royal [1] is a species of blue butterfly (Lycaenidae) found in South East Asia.

The butterfly occurs in India from Sikkim to Arunachal Pradesh.

The female is paler with a prominent white patch at the end cell of the forewing.

On the underside, the butterfly has a white band on a pale-brown background which broadens towards the costa and dorsum.

There is a lot of seasonal variation in the band width.