Acacia pusilla is a shrub of the genus Acacia and the subgenus Phyllodineae. It is native to an area along the south coast in the Wheatbelt and Goldfields-Esperance regions of Western Australia. The dome shaped shrub typically grows to a height of 0.1 to 0.3 metres (0.3 to 1.0 ft). It blooms from September to October and produces yellow flowers.