Hypolycaena pachalica, the eastern hairstreak, is a butterfly in the family Lycaenidae.

It is found in Uganda, eastern and northern Kenya, the Democratic Republic of the Congo (Ituri, Mahagi-Port, Kivu and Semliki), Tanzania, Malawi, Zambia, south-western Saudi Arabia and Yemen.

[2] The habitat consists of savanna and open forests.

Adults are attracted to flowers and males occasionally come to damp patches.

The larvae feed on Combretum constrictum and Talinum portulacifolium.