Acacia caerulescens, commonly known as limestone blue wattle, Buchan blue or Buchan blue wattle is a tree species that is endemic to Victoria, Australia. It grows to between 10 and 15 metres high and has phyllodes that are 4 to 8 cm long and 1.5 to 3 cm wide. The lemon yellow globular flowerheads appear in racemes from November to December in the species native range, followed by seed pods that are 5 to 12 cm long and 1.4 to 2.2 cm wide. The species was formally described in 1989 based on plant material collected near Buchan in Gippsland.