Acacia validinervia was previously regarded as a variety of A. notabilis. It differs mainly in the prominent lateral reticulate venation of the phyllodes. Acacia beckleri is closely allied but distinguished by its longer narrower phyllodes and larger flower-heads. Acacia pruinocarpa has similar phyllodes but differs in its inflorescences with sparsely arranged flower-heads on long peduncles.

A possible hybrid hetween A. notabilis and A. anceps occurs only in a small population in the hundred of Glynn on Eyre Peninsula.