Prosotas pia, the margined lineblue,[1] is a species of blue (Lycaenidae) butterfly found in Asia.

The butterfly occurs in India from in the Himalayas from Sikkim to Assam and Naga hills.

The range extends eastwards to Myanmar and southern Yunnan (Southwestern China).

It also occurs in Sundaland, Sulawesi and Serang in South-East Asia.

This Lycaenidae-related article is a stub.