Hypolycaena pachalica, the Eastern Hairstreak, is a butterfly in the Lycaenidae family. It was described by Butler in 1888. It is found in Uganda, eastern and northern Kenya, the Democratic Republic of Congo (Ituri, Mahagi-Port, Kivu and Semliki), Tanzania, Malawi, Zambia, south-western Saudi Arabia and Yemen. 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.