Phellodon sinclairii is a native tooth fungus found in beech forests of New Zealand.

It was first described by Miles Joseph Berkeley in 1867 as a species of Hydnum in Joseph Dalton Hooker's work Handbook of the New Zealand Flora.

Gordon Herriot Cunningham transferred the species to the genus Phellodon in 1958.

The cap surface is black with a whitish margin.

The crowded spines on the cap underside are up to 2 mm long, and run decurrently down the stipe.