Acompsia pyrenaella is a moth of the family Gelechiidae. It is found in the Pyrenees. The wingspan is 18–21 millimetres (0.71–0.83 in) for males and about 15 millimetres (0.59 in) for females. The forewings of the males are brown with groups of black scales. The hindwings are light grey. Females dark grey-brown forewings, mottled with light grey and with yellow and black scales. The hindwings are grey. Adults have been recorded on wing from early July to early August.