Synaphea diabolica is a shrub endemic to Western Australia.^[1]

Synaphea diabolica
Conservation status
Priority Three — Poorly Known Taxa (DEC)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Order:	Proteales
Family:	Proteaceae
Genus:	Synaphea
Species:	S. diabolica
Binomial name
Synaphea diabolica R.Butcher

The clumped and sprawling shrub typically grows to a height of 0.2 to 0.6 metres (1 to 2 ft) and produces yellow flowers.

It is found on undulating areas in the Darling Range and Wheatbelt region of Western Australia between Mundaring and Northam where it grows in gravelly soils over laterite.^[1]