Baeckea pentagonantha is a species of flowering plant in the family Myrtaceae and is endemic to near-coastal areas in the west of Western Australia.

It is an erect, spreading shrub that typically grows to a height of 0.25 to 2 metres (0.8 to 6.6 ft) and blooms between July and October producing white flowers.

[2] It is found on sand plains and river flats in the coastal parts of the Mid West region of Western Australia centred around Geraldton where it grows in sandy soils.

[2] Baeckea pentagonantha was first formally described by Ferdinand von Mueller in 1864 in his book Fragmenta Phytographiae Australiae from specimens collected by Augustus Oldfield near the Murchison River.

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