Acacia pycnocephala is a shrub of the genus Acacia and the subgenus Phyllodineae. It is native to an area in the Wheatbelt, Great Southern, South West and Goldfields-Esperance regions of Western Australia. The slender prickly shrub typically grows to a height of 0.25 to 0.6 metres (0.8 to 2.0 ft). It blooms from May to September and produces yellow flowers.